<PAGE>

    AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON AUGUST 29, 1997
 
                                                     REGISTRATION NO. 333-
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                            ------------------------
 
                                    FORM S-1
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                            ------------------------
                            HEALTHWORLD CORPORATION
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)
 
<TABLE>
<S>                                       <C>                                       <C>
                DELAWARE                                    7311                                   13-3922288
    (STATE OR OTHER JURISDICTION OF             (PRIMARY STANDARD INDUSTRIAL                    (I.R.S. EMPLOYER
     INCORPORATION OR ORGANIZATION)             CLASSIFICATION CODE NUMBER)                  IDENTIFICATION NUMBER)
</TABLE>
 
                            ------------------------
 
                           100 AVENUE OF THE AMERICAS
                            NEW YORK, NEW YORK 10013
                                 (212) 966-7640
              (ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER,
       INCLUDING AREA CODE, OF REGISTRANT'S PRINCIPAL EXECUTIVE OFFICES)
                            ------------------------
 
                                STEVEN GIRGENTI
               CHAIRMAN OF THE BOARD AND CHIEF EXECUTIVE OFFICER
                            HEALTHWORLD CORPORATION
                           100 AVENUE OF THE AMERICAS
                            NEW YORK, NEW YORK 10013
                                 (212) 966-7640
           (NAME, ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER,
                   INCLUDING AREA CODE, OF AGENT FOR SERVICE)
                            ------------------------
 
                                   Copies to:
 
<TABLE>
<S>                                                             <C>
                    HOWARD S. JACOBS, ESQ.                                          EDWARD D. SOPHER, ESQ.
                     ROSENMAN & COLIN LLP                                           STEPHEN E. OLDER, ESQ.
                      575 MADISON AVENUE                                  AKIN, GUMP, STRAUSS, HAUER & FELD, L.L.P.
                NEW YORK, NEW YORK 10022-2585                                         590 MADISON AVENUE

                     TEL: (212) 940-8800                                        NEW YORK, NEW YORK 10022-4616
                     FAX: (212) 940-8776                                             TEL: (212) 872-1000
                                                                                     FAX: (212) 872-1002
</TABLE>
 
                            ------------------------
 
     APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC: As soon as
practicable after the effective date of this Registration Statement.
 
     If any of the securities being registered on this form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, check the following box. / /
 
     If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, check the following box and
list the Securities Act registration statement number of the earlier effective
registration statement for the same offering: / /
 
     If this Form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, check the following box and list the Securities Act
registration number of the earlier effective registration statement for the same
offering: / /
 
     If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box: / /
                            ------------------------
 
                        CALCULATION OF REGISTRATION FEE
 
<TABLE>
<CAPTION>
                                          AMOUNT TO     PROPOSED MAXIMUM     PROPOSED MAXIMUM
       TITLE OF EACH CLASS OF                BE          OFFERING PRICE     AGGREGATE OFFERING        AMOUNT OF
     SECURITIES TO BE REGISTERED         REGISTERED       PER SHARE(1)           PRICE(1)          REGISTRATION FEE
<S>                                     <C>             <C>                 <C>                  <C>
Common Stock, $.01 par value(2)......     2,415,000           $9.50            $22,942,500            $6,952.27
</TABLE>
 
(1) Estimated solely for the purpose of calculating the registration fee
    pursuant to Rule 457(a) under the Securities Act of 1933.
 
(2) Includes 315,000 shares which may be purchased by the Underwriters to cover
    over-allotments, if any.
                            ------------------------
 
     THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(A) OF
THE SECURITIES ACT OF 1933 OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SECTION 8(A), MAY
DETERMINE.
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
<PAGE>
                            HEALTHWORLD CORPORATION
                             CROSS REFERENCE SHEET
                   PURSUANT TO ITEM 501(B) OF REGULATION S-K
 
<TABLE>
<CAPTION>
                         ITEM NUMBER AND
                       HEADING IN FORM S-1                                    LOCATION IN PROSPECTUS
      ------------------------------------------------------  ------------------------------------------------------
 
<C>   <S>                                                     <C>
 1.   Forepart of the Registration Statement and Outside
        Front Cover Page of Prospectus......................  Forepart; Outside Front Cover Page; Inside Cover Page;
                                                                Cross Reference Sheet
 
 2.   Inside Front and Outside Back Cover Pages of
        Prospectus..........................................  Inside Front Cover Page; Additional Information;
                                                                Outside Back Cover Page
 
 3.   Summary Information, Risk Factors and Ratio of
        Earnings to Fixed Charges...........................  Outside Front Cover Page; Prospectus Summary; Risk
                                                                Factors
 
 4.   Use of Proceeds.......................................  Prospectus Summary; Use of Proceeds
 
 5.   Determination of Offering Price.......................  Outside Front Cover Page; Underwriting
 
 6.   Dilution..............................................  Risk Factors; Dilution
 
 7.   Selling Security Holders..............................  *
 
 8.   Plan of Distribution..................................  Outside Front Cover Page; Underwriting
 
 9.   Description of Securities to be Registered............  Description of Capital Stock
 
10.   Interests of Named Experts and Counsel................  Legal Matters; Experts
 
11.   Information with Respect to the Registrant............  Outside Front Cover Page; Prospectus Summary; The
                                                                Consolidation; Risk Factors; Dividend Policy;
                                                                Dilution; Capitalization; Selected Pro Forma
                                                                Combined Financial Information; Selected Financial
                                                                Information of GHB&M and Milton; Management's
                                                                Discussion and Analysis of Financial Condition and
                                                                Results of Operations; Business; Management; Certain
                                                                Relationships and Related Transactions; Principal
                                                                Stockholders; Description of Capital Stock; Shares
                                                                Eligible for Future Sale; Financial Statements
 
12.   Disclosure of Commission Position on Indemnification
        for Securities Act Liabilities......................  *
</TABLE>
 

------------------
* Omitted because answer is not applicable or is negative.

<PAGE>
PROSPECTUS                                                 SUBJECT TO COMPLETION
AUGUST 29, 1997
 
                                2,100,000 SHARES
 
                                     [LOGO]
                            HEALTHWORLD CORPORATION
                                  COMMON STOCK
 
                         ------------------------------
 
     Healthworld Corporation (the 'Company') is hereby offering 2,100,000 shares
of its common stock, $.01 par value per share (the 'Common Stock'). It is
currently estimated that the initial public offering price for the Common Stock
will be between $8.00 and $9.50 per share. Prior to the Offering, there has been
no public market for the Common Stock of the Company. See 'Underwriting' for a
discussion of the factors considered in determining the initial public offering
price of the Common Stock. The Company has applied for quotation of the Common
Stock on The Nasdaq National Market under the symbol 'HWLD.'
 
                         ------------------------------
 
        THE COMMON STOCK OFFERED HEREBY INVOLVES A HIGH DEGREE OF RISK.
                    SEE 'RISK FACTORS' BEGINNING ON PAGE 6.
 
                         ------------------------------
 
THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES
   AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR
      HAS THE SECURITIES AND EXCHANGE COMMISSION OR ANY STATE
        SECURITIES COMMISSION PASSED UPON THE ACCURACY OR
           ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION
                         TO THE CONTRARY IS A CRIMINAL OFFENSE.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 
<TABLE>
<CAPTION>
                                                                  UNDERWRITING
                                          PRICE TO               DISCOUNTS AND              PROCEEDS TO
                                           PUBLIC                COMMISSIONS(1)              COMPANY(2)
<S>                               <C>                       <C>                       <C>
Per Share.......................             $                         $                         $
Total(3)........................             $                         $                         $
</TABLE>
 
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 
(1) Excludes a non-accountable expense allowance payable by the Company to

    Unterberg Harris and Pennsylvania Merchant Group Ltd, the representatives
    (the 'Representatives') of the several underwriters (the 'Underwriters'),
    equal to 1% of the gross proceeds of the Offering. The Company has agreed to
    indemnify the Underwriters against certain liabilities, including
    liabilities under the Securities Act of 1933, as amended. See
    'Underwriting.'
 
(2) Before deducting expenses of the Offering payable by the Company, estimated
    at $          .
 
(3) The Company has granted to the Underwriters an option, exercisable within 30
    days after the date of this Prospectus, to purchase up to 315,000 additional
    shares of Common Stock solely to cover over-allotments, if any. If such
    option is exercised in full, the total Price to Public, Underwriting
    Discounts and Commissions and Proceeds to Company will be $          ,
    $          and $          , respectively. See 'Underwriting.'
 
     The shares of Common Stock are offered by the Underwriters, subject to
receipt and acceptance of such shares by them. The Underwriters reserve the
right to reject any order in whole or in part. It is expected that the shares
will be ready for delivery in New York, New York, on or about              ,
1997.
 
                         ------------------------------
 
UNTERBERG HARRIS                                 PENNSYLVANIA MERCHANT GROUP LTD
 
                                           , 1997
<PAGE>
     [Three page fold out containing the Healthworld name and logo, various
pictures of services provided by the Company and advertising campaigns and
campaign materials prepared by the Company, and the following textual
statements: 'The Company provides a wide array of marketing and communications
services to its clients, ranging from the execution of a discrete marketing
project, such as designing product packaging, to taking responsibility for the
overall marketing message, which enables the Company to incorporate a wide
variety of its services into one integrated marketing campaign' and 'Healthworld
B.V. is a worldwide network of licensed independent marketing and communications
agencies through which the Company utilizes the creative talents of proven
agencies that have expertise and knowledge of particular countries or geographic
regions to develop consistent integrated multinational campaigns for its
clients.']

<PAGE>
             [CHART DEPICTING FUNCTIONAL STRUCTURE OF THE COMPANY]
 
     CERTAIN PERSONS PARTICIPATING IN THE OFFERING MAY ENGAGE IN TRANSACTIONS
THAT STABILIZE, MAINTAIN OR OTHERWISE AFFECT THE PRICE OF THE COMMON STOCK,
INCLUDING OVER-ALLOTMENT, STABILIZING AND SHORT-COVERING TRANSACTIONS IN SUCH
SECURITIES AND THE IMPOSITION OF A PENALTY BID IN CONNECTION WITH THE OFFERING.
FOR A DESCRIPTION OF THESE ACTIVITIES, SEE 'UNDERWRITING.'
 
     'Healthworld' and the Healthworld logo are registered trademarks for which
the Company holds a license. Trade names and trademarks of other companies

appearing in this Prospectus are the property of their respective holders.
 
                                       2
<PAGE>
                               PROSPECTUS SUMMARY
 
     On the effective date of the Offering made by this Prospectus, Healthworld
Corporation will acquire (the 'Consolidation'), in exchange for shares of its
Common Stock, all of the issued and outstanding common stock of each of
Girgenti, Hughes, Butler & McDowell, Inc. and its affiliated entities ('GHB&M')
and Milton Marketing Group Limited and its subsidiaries ('Milton'). Unless
otherwise indicated, all references herein to the 'Company' include GHB&M and
Milton and give effect to the Consolidation and all references herein to
'Healthworld' refer to Healthworld Corporation prior to the consummation of the
Consolidation. The following summary does not purport to be complete and is
qualified in its entirety by the more detailed information and financial
statements and the related notes appearing elsewhere in this Prospectus. Unless
otherwise indicated, all share, per share and financial information set forth
herein assume no exercise of the Underwriters' over-allotment option. All
statistical and financial information presented in this Prospectus with respect
to Milton has been converted into U.S. Dollars using an exchange rate as of June
30, 1997 of $1.67=pounds 1.00, except as otherwise provided herein and except
for such information contained in or derived from Milton's financial statements
included elsewhere herein. All references herein to industry financial and
statistical information are based on trade articles and industry reports that
the Company believes to be reliable, although there can be no assurance to that
effect.
 
                                  THE COMPANY
 
     The Company is a leading international marketing and communications
services company specializing in health care. The Company provides many of the
world's largest pharmaceutical and other health care companies with a
comprehensive range of integrated strategic marketing services designed to
accelerate the market acceptance of new products and to sustain marketability
throughout their life-cycles. The Company's communications services include
advertising and promotion, publishing, medical education, public relations,
consulting, interactive multimedia, database marketing and marketing research
services. The Company also offers contract sales services which are delivered
through dedicated and syndicated sales teams. The Company offers its clients
global reach and expertise through its operations in the United States and the
United Kingdom, and through Healthworld B.V., a world-wide network of licensed
independent communications agencies located in 12 other countries.
 
     The Company believes that its understanding of the scientific and medical
issues relating to its clients' products and its in-depth knowledge of the
health care industry and regulatory environment are competitive advantages and
are critical for developing the most effective marketing and communications
campaigns and strategies. The Company relies on its creative talent and utilizes
new media and technologies to continually develop better ways to effectively
promote its clients' products. GHB&M, which has consistently been recognized in
the industry as one of the top health care communications agencies, was named
'Agency of the Year' in 1993 and 1996 by Med Ad News, a leading medical
advertising and communications trade publication, and was a finalist for such

award in 1992 and 1994. GHB&M was also named 'Most Creative Agency' by Med Ad
News in 1995. The Company was one of the first companies to develop a
direct-to-consumer marketing ('DTC') campaign for a prescription drug, and
believes it is an industry leader in the development of DTC campaigns, as well
as marketing strategies and campaigns for 'switching' a drug from prescription
to over-the-counter status.
 
     Pharmaceutical and other health care companies have been increasing their
spending on marketing and communications services and, in response to
cost-containment pressures, are increasingly outsourcing certain labor
intensive, high cost services, including marketing and sales and research
functions. Worldwide spending by pharmaceutical and biotechnology companies on
promotional marketing and contract sales is estimated to reach $5.9 billion in
1997. The Company believes that these spending levels will continue to increase
as companies seek to recoup the high costs of product development, maximize
sales, develop brand loyalty and achieve a high market share in the shortest
possible time period due to a limited patent life on new products. In addition,
cost constraints imposed as a result of health care reform and the emergence of
managed care have forced pharmaceutical and other health care companies to spend
more on marketing and communications services to educate the market as to
cost-effectiveness as well as the safety and efficacy of their products.
 
                                       3
<PAGE>
     Furthermore, the use of DTC to promote prescription drugs has grown rapidly
and is expected to continue to grow in the future. In 1996, the first year in
which more money was spent on DTC than on advertising to physicians,
pharmaceutical companies spent approximately $600 million on DTC, which is twice
as much as was spent in 1995 and almost 10 times more than in 1991. Figures for
the first few months of 1997 suggest that the total may double again and exceed
$1.0 billion for the year.
 
     The Company's contract sales teams form a network of trained professionals
that provides clients with substantial flexibility in selecting the extent and
costs of promoting products as well as such clients' level of involvement in
managing the sales effort. The Company believes that the speed of recruitment,
quality of training and management of sales representatives, supported by
advanced information technology, are key to providing clients with a sales force
tailored to meet their geographic and scheduling needs. Currently, the Company's
contract sales organization operates only in the United Kingdom and provides its
services primarily to consumer products companies, utilities and other
non-health care related companies. In the first quarter of 1997, the Company
began providing contract sales services in the United Kingdom to pharmaceutical
and other health care companies. The Company intends to expand its contract
sales organization into the United States. The Company believes that such
expansion will enable it to complement its existing communications services with
a flexible sales force designed to augment its clients' sales activities.
 
     The Company's strategy is to capitalize on continued growth in marketing
and communications spending by pharmaceutical and other health care companies by
(i) maintaining and enhancing its creative excellence and technical expertise,
(ii) offering its clients a comprehensive range of integrated services, (iii)
continuing to specialize in health care, (iv) increasing its contract sales
services, and (v) further expanding globally. The Company intends to implement

its strategy through internal development and potential acquisitions.
 
     The Company's principal executive offices are located at 100 Avenue of the
Americas, New York, New York 10013. The Company's telephone number is (212)
966-7640.
 
                                  THE OFFERING
 
<TABLE>
<S>                                            <C>
Common Stock offered by the Company..........  2,100,000 shares
 
Common Stock to be outstanding immediately
  after the Offering.........................  7,100,000 shares(1)(2)
 
Use of Proceeds..............................  For working capital and general corporate purposes, including
                                               potential acquisitions. See 'Use of Proceeds.'
 
Nasdaq National Market Symbol................  HWLD
</TABLE>
 
------------------
(1) Includes 5,000,000 shares of Common Stock to be issued in connection with
    the Consolidation.
 
(2) Excludes 710,000 shares of Common Stock reserved for issuance upon the
    exercise of stock options which may be granted under the Company's 1997
    Stock Option Plan (the 'Stock Option Plan'), none of which have been granted
    to date. As of the effective date of the Offering, the Company will grant
    options under the Stock Option Plan to purchase up to an aggregate of
    shares of Common Stock, at an exercise price per share equal to the initial
    public offering price. See 'Management--Stock Option Plan.'
 
                                       4
<PAGE>
                SUMMARY PRO FORMA COMBINED FINANCIAL INFORMATION
 
     The following summary pro forma combined financial information gives effect
to the Consolidation, among other events, as more fully described in 'The
Consolidation,' and should be read in conjunction with the Company's unaudited
Pro Forma Combining Financial Statements and notes thereto, the Combined
Financial Statements of GHB&M and notes thereto, the Consolidated Financial
Statements of Milton and notes thereto and 'Management's Discussion and Analysis
of Financial Condition and Results of Operations' contained elsewhere in this
Prospectus. The Consolidation will be accounted for as a 'pooling of interests.'
Such financial data covers periods when GHB&M and Milton were not under common
control or management and may not be indicative of results that would have been
reported had the Consolidation and the other pro forma adjustments occurred nor
may it be indicative of the Company's future financial position or operating
results.
 
<TABLE>
<CAPTION>
                                                                                                SIX MONTHS ENDED

                                                                 YEAR ENDED DECEMBER 31,            JUNE 30,
                                                              -----------------------------    ------------------
                                                               1994       1995       1996       1996       1997
                                                              -------    -------    -------    -------    -------
                                                                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
<S>                                                           <C>        <C>        <C>        <C>        <C>
STATEMENT OF INCOME DATA:
Revenues...................................................   $13,081    $16,767    $24,209    $11,322    $14,783
Operating expenses:
  Salaries and related costs...............................     7,890      9,422     15,392      7,525     10,400
  Other operating expenses.................................     3,727      4,904      5,615      2,797      3,000
                                                              -------    -------    -------    -------    -------
                                                               11,617     14,326     21,007     10,322     13,400
                                                              -------    -------    -------    -------    -------
Income from operations.....................................     1,464      2,441      3,202      1,000      1,383
Income before provision for income taxes...................     1,450      2,439      3,133      1,048      1,404
Net income(1)..............................................   $   837    $ 1,401    $ 1,828    $   623    $   820
                                                              -------    -------    -------    -------    -------
                                                              -------    -------    -------    -------    -------
Earnings per share.........................................   $  0.17    $  0.28    $  0.37    $  0.12    $  0.16
                                                              -------    -------    -------    -------    -------
                                                              -------    -------    -------    -------    -------
Shares used in computing earnings per share................     5,000      5,000      5,000      5,000      5,000
</TABLE>
 
<TABLE>
<CAPTION>
                                                                                                JUNE 30, 1997
                                                                                         ---------------------------
                                                                                                        PRO FORMA
                                                                                         PRO FORMA    AS ADJUSTED(2)
                                                                                         ---------    --------------
                                                                                               (IN THOUSANDS)
<S>                                                                                      <C>          <C>
BALANCE SHEET DATA:
Working capital.......................................................................    $    48        $ 15,953
Total assets..........................................................................     19,916          35,821
Long-term debt, including current portion.............................................      1,324           1,324
Stockholders' equity..................................................................      5,557          21,462
</TABLE>
 
------------------
(1) Immediately upon consummation of the Consolidation, the status of the
    companies comprising GHB&M as 'S Corporations' under Subchapter S of the
    Internal Revenue Code of 1986, as amended (the 'Code'), will terminate. The
    pro forma provision for income taxes reflects a provision for federal income
    taxes as if each of such entities were a 'C Corporation' rather than an 'S
    Corporation' for such periods. See 'The Consolidation.'
 
(2) Gives effect to the Offering at an assumed initial public offering price of
    $8.75 per share and the application of the estimated net proceeds therefrom.
    See 'Use of Proceeds.'
 
                                       5

<PAGE>
                                  RISK FACTORS
 
     An investment in the Common Stock offered hereby involves a high degree of
risk and immediate substantial dilution. In addition to the other information
contained in this Prospectus, prospective investors should carefully consider
the following considerations and risks in evaluating an investment in the
Company.
 
     DEPENDENCE ON CERTAIN KEY CLIENTS.  The Company's revenues are highly
dependent upon the advertising, sales and marketing expenditures of
pharmaceutical and other health care companies. Generally, clients are not bound
to an individual marketing and communications company, and any client of the
Company could at any time in the future and for any reason, including a
prolonged economic recession or regulatory problems with respect to a product,
reduce its marketing budget, transfer its business to another agency or take
in-house all or part of the business performed by the Company. The Company
develops long-term relationships with a select group of clients, and a large
portion of its revenues are concentrated among a small number of major clients
which may engage the Company to provide services only for specific products.
However, the Company generally is retained to provide marketing and
communications services with respect to multiple products from each of such
clients, and the loss of business with respect to any one product from any of
such clients would not necessarily affect the Company's business with respect to
other products for which the Company provides its services.
 
     For the year ended December 31, 1996 and the six months ended June 30,
1997, the five largest clients of the Company represented an aggregate of 50%
and 46%, respectively, of the Company's pro forma combined revenues. For the
year ended December 31, 1996, Wyeth-Ayerst Laboratories, Ortho/McNeil
Pharmaceuticals (a division of Johnson & Johnson) and Kraft Jacobs Suchard
Limited accounted for an aggregate of approximately 25%, 9% and 6%,
respectively, of the Company's pro forma combined revenues. For the six months
ended June 30, 1997, Wyeth-Ayerst Laboratories, Ionica plc and Ortho/McNeil
Pharmaceuticals accounted for approximately 18%, 9% and 7%, respectively, of the
Company's pro forma combined revenues. The loss of any of these clients (none of
which has engaged the Company on an exclusive basis) or one or more of the
Company's other clients, the deterioration of the Company's relationships with
any of these clients, a decline in the business of any of such clients or a
decline in such clients' marketing and communications spending (either generally
or with respect to specific products for which the Company is engaged) could
have a material adverse effect on the Company's business, financial condition or
results of operations. See 'Business--Clients' and 'Business--Competition.'
 
     ABSENCE OF COMBINED OPERATING HISTORY.  Although GHB&M and Milton have been
operating in the advertising, marketing and communications industry since April
1986 and August 1978, respectively, and have been working together through their
affiliation with Healthworld B.V. since 1993, Healthworld, which was
incorporated in September 1996, has conducted no operations and generated no
revenues to date. In connection with the Consolidation, Healthworld will enter
into agreements to acquire GHB&M and Milton on the effective date of the
Offering. GHB&M and Milton have been operating as separate independent entities,
and there can be no assurance that the Company will be able to successfully
integrate the operations of these businesses, institute the necessary

Company-wide systems and procedures to successfully manage the combined
enterprise on a profitable basis, or effectively implement its growth strategy.
The unaudited pro forma combining historical financial results of the Company
cover periods when GHB&M, Milton and Healthworld were not under common control
or management and, therefore, may not be indicative of results that would have
been reported by the Company had such events occurred on the dates specified,
nor may they be indicative of the Company's future financial or operating
results. The inability of the Company to successfully integrate GHB&M and Milton
would have a material adverse effect on the Company's business, financial
condition and results of operations and would make it unlikely that the
Company's growth strategy will be successful. See 'The Consolidation,'
'Management's Discussion and Analysis of Financial Condition and Results of
Operations,' the Company's Pro Forma Combining Financial Statements, the
Combined Financial Statements of GHB&M and the related notes thereto, and the
Consolidated Financial Statements of Milton and the related notes thereto.
 
     MANAGEMENT OF GROWTH; ACQUISITION RISKS.  The Company's growth will depend
on a number of factors, including the Company's ability to maintain the high
quality of the services it provides to customers and to increase the number of
services it provides to existing clients, as well as to recruit, motivate and
retain highly skilled creative, technical and marketing personnel. Competition
for highly qualified personnel in the health care
 
                                       6
<PAGE>
communications industry is intense and the inability to attract and retain key
personnel could have a material adverse effect upon the Company's business,
results of operations or financial condition.
 
     The Company also intends to grow through the acquisition of businesses
specializing primarily in servicing the pharmaceutical and other health care
industries. Although the Company believes that opportunities for future
acquisitions are currently available, due to considerable acquisitions and
consolidations in the marketing and communications industry in recent years,
increased competition for acquisition candidates exists and may continue in the
future. Consequently, there may be fewer acquisition opportunities available to
the Company as well as higher acquisition prices. There can be no assurance that
the Company will be able to identify, acquire, manage or successfully integrate
acquired businesses without substantial costs, delays or operational or
financial problems. While the Company regularly evaluates and discusses
potential acquisitions, the Company currently has no understandings, commitments
or agreements with respect to any acquisitions. The Company may be required to
obtain additional financing to fund future acquisitions. The Company has no
current commitments or arrangements for such additional financing and there can
be no assurance that the Company will be able to obtain additional financing on
acceptable terms or at all. See 'Management's Discussion and Analysis of
Financial Condition and Results of Operations--Liquidity and Capital Resources'
and 'Business--Strategy.'
 
     FLUCTUATIONS IN QUARTERLY OPERATING RESULTS.  The Company's results of
operations have been and can be expected to be subject to quarterly
fluctuations. Generally, the Company's revenues and profits are lowest in the
first quarter and highest in the fourth quarter. The Company's quarterly revenue
trends result from a number of factors, including, among other things, the

timing of commencement, completion or cancellation of major projects and
industry billing practices which are tied to clients' annual marketing budgets,
while the Company's communications services expenses generally remain constant.
The Company's quarterly results may fluctuate as a result of a number of
additional factors, including delays or costs associated with acquisitions,
government regulatory initiatives and conditions in the health care industry
generally. The Company believes that quarterly comparisons of its financial
results should not be relied upon as an indication of future performance. See
'Management's Discussion and Analysis of Financial Condition and Results of
Operations--Quarterly Operating Results.'
 
     COMPETITION; INDUSTRY CONSOLIDATION.  The health care marketing and
communications industry throughout the United States and Europe is highly
competitive. The Company competes with other marketing and communications firms,
including international and local full-service and specialty marketing and
communications firms and, with respect to contract sales and marketing services,
with in-house sales departments of its clients and other contract sales and
marketing organizations. The Company has in the past and will in the future be
unable to pursue certain marketing and other potential business opportunities
because such opportunities would require the Company to provide services to
direct competitors of existing Company clients.
 
     Consolidation within the pharmaceutical and health care industries as well
as a trend by pharmaceutical and health care companies to allocate outsourcing
of sales, marketing and communications services to fewer organizations, has
heightened the competition among such service providers for a smaller number of
clients. In addition, many of the larger consumer products marketing and
communications companies have acquired health care marketing and communications
companies, which themselves have been increasingly consolidating in recent
years. Many of these companies have substantially greater financial resources,
personnel and facilities than the Company. In addition, if the previously
described consolidation trends continue, the Company may face greater
competition for clients. Although the Company believes it is able to compete on
the basis of the quality of its creative product, service, reputation and
personal relationships with clients, there can be no assurance that the Company
will be able to maintain its competitive position in the industry. See
'Business--Competition.'
 
     EXPANSION OF CONTRACT SALES SERVICES.  Currently, the Company's contract
sales organization operates only in the United Kingdom and provides its services
primarily to consumer products companies, utilities and other nonhealth care
related companies. In March 1997, the Company began providing contract sales
services in the United Kingdom to pharmaceutical and other health care companies
to take advantage of the increased use by such companies in the United Kingdom
of contract sales forces to market their products. In addition, the Company
currently intends to develop a contract sales organization in the United States
to provide contract sales services to pharmaceutical and other health care
companies. The successful expansion of the Company's contract sales operations
in the United Kingdom and in the United States will be dependent on a number of
factors,
 
                                       7
<PAGE>
including (i) its ability to effectively compete against the in-house sales

departments of pharmaceutical companies and contract sales organizations
specializing in pharmaceutical and other health care products; (ii) the hiring
and training of qualified management personnel; and (iii) the ability to
integrate such contract sales operations into the Company's current structure.
An inability to manage future growth, compete effectively, or successfully
integrate such contract sales operations could have a material adverse effect on
the Company's business, financial condition or results of operations. See
'Business--Strategy' and 'Business--Competition.'
 
     DEPENDENCE ON KEY PERSONNEL.  The Company is dependent on the efforts and
abilities of its senior management, including Steven Girgenti, its Chairman and
Chief Executive Officer, and William Leslie Milton, its Vice Chairman and
President. The loss of the services of either of Mr. Girgenti or Mr. Milton, or
any other key employee could have a material adverse effect on the Company.
Although the Company intends to obtain key person life insurance on the lives of
Messrs. Girgenti and Milton in the amounts of $4.0 million and $2.0 million,
respectively, as to which the Company will be the sole beneficiary, there can be
no assurance that such policies, if procured, would adequately compensate for
the loss of such individuals. Each of Messrs. Girgenti and Milton and certain
other executive officers of the Company will enter into employment agreements
with the Company upon the consummation of the Consolidation. Each member of the
Company's management and other key employees have or will have executed
confidentiality and non-solicitation agreements that restrict such persons from
misappropriating confidential information during such person's term of
employment and thereafter and from soliciting the Company's clients, prospects
or employees following termination of employment. Notwithstanding such
agreements, in the event of loss of any such personnel there can be no assurance
that the Company would be able to prevent the unauthorized disclosure or use of
its knowledge, practices, procedures or client lists. See 'Management.'
 
     UNCERTAINTY IN HEALTH CARE INDUSTRY AND POSSIBLE HEALTH CARE REFORM.  The
health care industry is subject to changing political, economic and regulatory
influences that may affect pharmaceutical and other health care companies,
particularly with respect to spending by such companies on marketing and
communications services to promote their products. Numerous governments have
undertaken efforts to control growing health care costs through legislation,
regulation and voluntary agreements with medical care providers and
pharmaceutical and other health care product companies. Implementation of
government health care reform may adversely affect marketing expenditures by
pharmaceutical and other health care companies which could decrease the business
opportunities available to the Company. Management is unable to predict the
likelihood of health care reform legislation being enacted or the effects such
legislation would have on the Company. In addition, the success of the Company's
growth strategy depends on its ability to take advantage of certain industry
trends, including continued increases in overall spending levels by
pharmaceutical and other health care companies for marketing and communications
services. Such growth in spending levels has evolved rapidly in recent years and
the Company is unable to predict whether such growth in spending will continue
at present levels or at all. The Company's results of operations could be
materially adversely affected in the event the Company is unable to respond
effectively to the enactment of health care reform legislation or changing
industry trends which may affect future spending levels by pharmaceutical and
other health care companies for marketing and communications services. See
'Business--Industry Background.'

 
     INSURANCE AND POTENTIAL LITIGATION.  The Company, as part of its business,
develops marketing and communications campaigns and materials with respect to
pharmaceutical and other health care products, including newly developed drugs
and other health care products. As a result, the Company may, in the future, be
subject to certain types of litigation, including claims arising from false or
misleading statements made with respect to the use or efficacy of such
pharmaceutical and health care products. Certain of the Company's contracts with
its clients provide for the client to indemnify the Company against such
liabilities. In addition, the Company maintains liability insurance covering
such liabilities, and the Company believes that such liability insurance
coverage is adequate. In certain limited circumstances, however, the Company is
obligated to indemnify its clients with respect to such claims and liabilities.
The Company could be materially and adversely affected if it were required to
pay damages or bear the costs of defending any claim outside the scope of or in
excess of a contractual indemnification provision or beyond the level of
insurance coverage or in the event that an indemnifying party does not fulfill
its indemnification obligations. Even if any such claim was without merit,
defending against such claim could result in adverse publicity and diversion of
management's time and attention and could have a material adverse effect on the
Company.
 
                                       8
<PAGE>
     CONTROL OF THE COMPANY.  Upon completion of the Consolidation and the
Offering, certain directors and executive officers of the Company will
collectively own approximately 70% of the Company's outstanding Common Stock.
Consequently, such stockholders will be able to control the outcome of matters
submitted to a vote by the Company's stockholders, such as the election of the
Company's Board of Directors, and control the direction and future operations of
the Company. Such concentrations of share ownership may have the effect of
discouraging, delaying or preventing a change in control of the Company. See
'Principal Stockholders.'
 
     DILUTION.  Immediately upon issuance of the Common Stock offered hereby at
an assumed initial public offering price of $8.75 per share, purchasers of the
Common Stock will experience immediate and substantial dilution in the pro forma
net tangible book value per share of Common Stock of $6.24. See 'Dilution.'
 
     FOREIGN EXCHANGE RATE RISKS.  Exchange rates for some local currencies in
countries where the Company currently operates or may operate in the future may
fluctuate in relation to the U.S. Dollar and such fluctuations may have an
adverse effect on the Company's earnings or assets when local currencies are
translated into U.S. Dollars. In particular, because Milton currently operates
only in the United Kingdom, the Company is susceptible to foreign exchange rate
fluctuations between the British Pound Sterling and the U.S. Dollar. Any
weakening of the value of a local currency, including the British Pound
Sterling, against the U.S. Dollar could result in lower revenues and earnings
for the Company when such local currencies are translated into U.S. Dollars.
Therefore, there can be no assurance that currency exchange rates will not have
a material adverse effect on the Company. See 'Management's Discussion and
Analysis of Financial Condition and Results of Operations.'
 
     NO PRIOR MARKET FOR THE COMMON STOCK; DETERMINATION OF OFFERING

PRICE.  Prior to the Offering, there has been no public market for the Common
Stock of the Company. The initial public offering price for the Common Stock
will be determined through negotiations between the Company and the
Representatives based on such factors as the earnings prospects of the Company
and prevailing market conditions, and does not necessarily bear any relationship
to the Company's book value, past operating results or other established
criteria of value. Such price may not be indicative of the market price of the
Common Stock after the Offering has been consummated. The Company has applied
for the listing of the Common Stock on The Nasdaq National Market under the
symbol 'HWLD'. There can be no assurance that an active trading market for the
Common Stock will be established, or if so established, sustained. See
'Underwriting.'
 
     After the Offering, the market price of the Common Stock may be subject to
significant fluctuations in response to numerous factors, including, but not
limited to, variations in the annual or quarterly financial results of the
Company, changes by financial research analysts in their estimates of the
earnings of the Company, conditions in the economy in general or in the
Company's industry in particular, unfavorable publicity or changes in applicable
laws and regulations (or judicial or administrative interpretations thereof)
affecting the Company or the health care communications industry. From
time-to-time, the stock market experiences significant price and volume
volatility, which may affect the market price of the Common Stock for reasons
unrelated to the Company's performance.
 
     SHARES ELIGIBLE FOR FUTURE SALE.  Upon completion of the Offering, there
will be 7,100,000 shares of Common Stock outstanding, of which the 2,100,000
shares sold pursuant to the Offering will be tradeable without restriction by
persons other than 'affiliates' of the Company. The remaining 5,000,000 shares
of Common Stock will be issued in connection with the Consolidation and will be
'restricted' securities within the meaning of the Securities Act of 1933, as
amended (the 'Securities Act'), and may not be sold in the absence of
registration under the Securities Act or an exemption therefrom, including the
exemptions contained in Rule 144 under the Securities Act. No prediction can be
made as to the effect, if any, that future sales of shares of Common Stock will
have on the market price of the Common Stock prevailing from time to time. Sales
of substantial amounts of Common Stock, or the perception that these sales could
occur, could adversely affect prevailing market prices for the Common Stock and
could impair the ability of the Company to raise additional capital through the
sale of its equity securities or through debt financing. The Company and its
officers and directors and the stockholders of GHB&M and Milton have each agreed
to enter into agreements (the 'Lock-up Agreements') under which they will agree
not to offer, sell or otherwise dispose of any shares of Common Stock or other
securities of the Company for a period of 180 days commencing upon the date of
this Prospectus, without the prior written consent of Unterberg Harris, other
than sales or issuances by the Company pursuant to the exercise of the
Underwriters' over-allotment option or pursuant to the grants of stock options
under the Company's 1997
 
                                       9
<PAGE>
Stock Option Plan. Thereafter, shares of Common Stock held by the stockholders
of GHB&M and Milton may be sold under Rule 144 under the Securities Act, subject
to the volume, manner of sale and other restrictions of Rule 144. In addition,

the Company has granted to such stockholders unlimited piggy-back registration
rights with respect to such shares, commencing one year from the date of this
Prospectus. See 'Shares Eligible for Future Sale' and 'Underwriting.'
 
     CERTAIN ANTI-TAKEOVER PROVISIONS.  The Company's Certificate of
Incorporation authorizes the Board of Directors of the Company to issue
preferred stock in one or more series with such rights and preferences as may be
determined from time-to-time by the Board of Directors. Accordingly, the Board
of Directors may, without stockholder approval, issue shares of preferred stock
with voting, dividend, liquidation, conversion or other rights which could
adversely affect the voting power or other rights of the holders of Common
Stock. Although the Company does not currently intend to issue any shares of
preferred stock, there can be no assurance that the Company will not do so in
the future. The ability to issue preferred stock as described above, as well as
certain applicable provisions of the Delaware General Corporation Law relating
to business combinations, may have the effect of rendering more difficult,
delaying, discouraging or preventing an acquisition of the Company or change in
control of the Company. See 'Description of Capital Stock.'
 
     ABSENCE OF DIVIDENDS.  The Company has no current intention to pay
dividends on its Common Stock and anticipates that, for the foreseeable future,
working capital and earnings, if any, will be retained to finance the expansion
of its business and for general corporate purposes. See 'Dividend Policy' and
'Description of Capital Stock.'
 
                                       10
<PAGE>
                               THE CONSOLIDATION
 
     Healthworld, which was incorporated in Delaware on September 12, 1996, was
formed to acquire GHB&M and Milton in the Consolidation, and has conducted no
operations to date. Prior to the consummation of the Offering, Healthworld will
enter into separate Agreements and Plans of Organization (the 'Consolidation
Agreements') with the stockholders of GHB&M and Milton pursuant to which, on the
effective date of the Offering, Healthworld will acquire all of the issued and
outstanding stock of each of GHB&M and Milton from the stockholders of GHB&M and
Milton in exchange for an aggregate of 5,000,000 shares of Common Stock of the
Company, at which time GHB&M and Milton will become wholly-owned subsidiaries of
Healthworld. See 'Principal Stockholders.'
 
     The Consolidation will be accounted for as a pooling of interests, which
method of accounting assumes that GHB&M and Milton have been combined from the
Company's inception and restates the historical financial statements for the
Company for the periods prior to the consummation of the Consolidation as though
GHB&M and Milton had been combined from the Company's inception.
 
     Pursuant to the Consolidation Agreements, the stockholders of GHB&M and
Milton will agree not to sell any of the Common Stock to be received by them in
the Consolidation in a 'Private Sale' without first offering to the stockholders
of GHB&M and Milton, respectively, and then to stockholders of Milton and GHB&M,
respectively, a right of first refusal to purchase such shares. Private Sales
are defined to include all transfers other than (i) sales of Common Stock
pursuant to Rule 144 under the Securities Act, (ii) sales pursuant to an
offering registered under the Securities Act, (iii) transfers in connection with

a merger, consolidation or sale of all or substantially all of the assets of the
Company, or (iv) permitted transfers to certain immediate family members and
other relatives. The stockholders of GHB&M and Milton also will agree not to
compete with the Company for a five-year period commencing on the effective date
of the Offering. In addition, members of the Company's management have or will
have entered into agreements pursuant to which they will not compete with the
Company during their employment with the Company and for a certain time period
thereafter. See 'Management--Employment Agreements.'
 
     Prior to the consummation of the Consolidation, the companies comprising
GHB&M (other than Syberactive, Inc. ('Syberactive'), which is treated as a C
Corporation) elected to be treated as S Corporations under the Code, pursuant to
which income or loss of each of such companies was allocated to its stockholders
by inclusion in their respective individual income tax returns. Immediately upon
consummation of the Consolidation, the status of each of the companies
comprising GHB&M as S Corporations will terminate and each of the companies
comprising GHB&M will then be subject to Federal and state income taxes at
applicable corporate rates.
 
     In connection with the termination of the status of each of the companies
comprising GHB&M as S Corporations, GHB&M is currently negotiating to enter into
an agreement which will provide that GHB&M will, prior to the consummation of
the Consolidation, sell approximately $2.5 million of its accounts receivable to
an unaffiliated financial institution at a negotiated discount rate (the
'Accounts Receivable Sale'). Immediately prior to the consummation of the
Consolidation, GHB&M will make distributions (the 'S Corporation Distributions')
to its stockholders of approximately $3.5 million in the aggregate from existing
cash balances for the payment by such stockholders of taxes due on S Corporation
earnings.
 
                                       11
<PAGE>
                                USE OF PROCEEDS
 
     The net proceeds from the sale of the 2,100,000 shares of Common Stock
offered hereby, at an assumed initial public offering price of $8.75 per share,
are estimated to be approximately $15.9 million, after deducting underwriting
discounts and commissions and other estimated expenses payable by the Company in
connection with the Offering (or approximately $18.4 million if the
Underwriters' over-allotment option is exercised in full). The Company intends
to use the net proceeds for working capital and general corporate purposes,
including (i) funding working capital needs which will result from the Accounts
Receivable Sale to be undertaken in connection with the S Corporation
Distributions of approximately $3.5 million, and (ii) for potential
acquisitions. The Company regularly evaluates and discusses potential
acquisitions. While the Company believes that opportunities for future
acquisitions are currently available, it currently has not entered into any
commitment, agreement or understanding with any third party with respect to any
possible acquisition, and there can be no assurance that the Company will be
able to identify or acquire suitable acquisition candidates, or that if
identified such acquisition candidate will be acquired by the Company or
successfully and profitably integrated into the Company. Pending use of the net
proceeds for the foregoing purposes, the Company intends to invest the net
proceeds in short-term, U.S. Dollar denominated, investment grade

interest-bearing securities. See 'The Consolidation,' 'Management's Discussions
and Analysis of Financial Condition and Results of Operations' and
'Business--Strategy--Growth Through Acquisitions.'
 
                                DIVIDEND POLICY
 
     Healthworld has never declared or paid a dividend on its Common Stock. The
companies comprising GHB&M, as S Corporations (other than Syberactive, which is
treated as a C Corporation), made cash distributions on their common stock to
the stockholders of GHB&M of an aggregate of $209,000 in 1995, $1.5 million in
1996, $497,000 through June 30, 1997, and, immediately prior to the consummation
of the Consolidation, will make the S Corporation Distributions of approximately
$3.5 million. The companies comprising Milton made cash distributions on their
common stock to the stockholders of Milton of an aggregate of $101,000 in the
1995 fiscal year, none in the 1996 fiscal year and $55,000 through June 30,
1997.
 
     After the consummation of the Consolidation, the Company intends to retain
all earnings, if any, to finance the expansion of its business and for general
corporate purposes, including future acquisitions, and does not anticipate
paying any cash dividends on its Common Stock for the foreseeable future. Any
future determination to pay cash dividends will be at the discretion of the
Board of Directors and will be dependent on the Company's financial condition,
results of operations, financial requirements and such other factors as the
Board of Directors deems relevant.
 
                                       12
<PAGE>
                                    DILUTION
 
     At June 30, 1997, the Company had a pro forma net tangible book value of
$1.9 million, or $0.38 per share of Common Stock. Pro forma net tangible book
value per share is, after giving effect to the Consolidation and the S
Corporation Distributions, the Company's total pro forma tangible assets less
its pro forma total liabilities, divided by the number of shares of outstanding
Common Stock. Pro forma tangible assets are defined as the pro forma assets of
the Company, excluding intangible assets, such as goodwill. After giving effect
to the sale by the Company of 2,100,000 shares of Common Stock offered hereby at
an assumed initial public offering price of $8.75 per share (and after deducting
underwriting discounts and commissions and Offering expenses payable by the
Company), the pro forma net tangible book value of the Company at June 30, 1997
would have been approximately $17.8 million or $2.51 per share. This represents
an immediate increase in pro forma net tangible book value of $2.13 per share to
existing stockholders and an immediate dilution of $6.24 per share to new
investors. Dilution represents the difference between the initial public
offering price paid by purchasers in the Offering and the net tangible book
value per share immediately after completion of the Offering. The following
table illustrates this per share dilution:
 
<TABLE>
<S>                                                                             <C>      <C>
Initial public offering price per share......................................            $8.75
  Pro forma net tangible book value per share before the Offering............   $0.38
  Increase in pro forma net tangible book value per share attributable to the

     sale of the Common Stock offered hereby.................................    2.13
                                                                                -----
Pro forma net tangible book value per share after the Offering...............             2.51
                                                                                         -----
Dilution per share to new investors..........................................            $6.24
                                                                                         -----
                                                                                         -----
</TABLE>
 
     The following table sets forth, on a pro forma basis as of June 30, 1997,
after giving effect to the Consolidation and the S Corporation Distributions, a
comparison of the number of shares of Common Stock acquired from the Company,
the total consideration paid to the Company and the respective average purchase
price per share paid by existing stockholders and new investors. The following
computations are based on an assumed initial public offering price of $8.75 per
share, before deducting the underwriting discounts and commissions and estimated
Offering expenses payable by the Company.
 
<TABLE>
<CAPTION>
                                             SHARES PURCHASED       TOTAL CONSIDERATION
                                           --------------------    ----------------------        AVERAGE
                                            NUMBER      PERCENT      AMOUNT       PERCENT    PRICE PER SHARE
                                           ---------    -------    -----------    -------    ---------------
<S>                                        <C>          <C>        <C>            <C>        <C>
Existing stockholders...................   5,000,000      70.4%    $ 5,557,000(1)   23.2%         $1.11
New investors...........................   2,100,000      29.6%     18,375,000      76.8%          8.75
                                           ---------    -------    -----------    -------
  Total.................................   7,100,000     100.0%    $23,932,000     100.0%
                                           ---------    -------    -----------    -------
                                           ---------    -------    -----------    -------
</TABLE>
 
------------------
(1) Represents the combined stockholders' equity of GHB&M and Milton before the
    Offering. See 'The Consolidation.'
 
                                       13
<PAGE>
                                 CAPITALIZATION
 
     The following table sets forth the capitalization of the Company at June
30, 1997, which, pro forma, gives effect to the Consolidation and the S
Corporation Distributions, and pro forma as adjusted, gives effect to the
Consolidation, the S Corporation Distributions and the sale of 2,100,000 shares
of Common Stock offered hereby at an assumed initial public offering price of
$8.75 per share and the application of the estimated net proceeds therefrom. See
'The Consolidation,' 'Use of Proceeds' and 'Selected Pro Forma Financial
Information.' This table should be read in conjunction with the Pro Forma
Combining Financial Statements of the Company and the related notes thereto
included elsewhere in this Prospectus.

<TABLE>
<CAPTION>
                                                                              JUNE 30, 1997
                                                                    ---------------------------------
                                                                                PRO FORMA
                                                                    ---------------------------------
                                                                    (IN THOUSANDS, EXCEPT SHARE DATA)
<S>                                                                 <C>
Long-term obligations, less current maturities...................                $   582
Stockholders' equity:
  Preferred Stock, $.01 par value, 1,000,000 shares authorized,
     no shares outstanding(1)....................................                     --
  Common Stock, $.01 par value, 20,000,000 shares authorized;
     5,000,000 shares outstanding, pro forma; 7,100,000 shares
     outstanding, pro forma as adjusted(1).......................                     50
  Additional paid-in capital.....................................                  4,581
  Retained earnings..............................................                    926
                                                                                 -------
     Total stockholders' equity..................................                  5,557
                                                                                 -------
     Total capitalization........................................                $ 6,139
                                                                                 -------
                                                                                 -------
 
<CAPTION>
                                                                              JUNE 30, 1997
                                                                    ---------------------------------
                                                                                PRO FORMA
                                                                               AS ADJUSTED
                                                                    ---------------------------------
                                                                    (IN THOUSANDS, EXCEPT SHARE DATA)
<S>                                                                 <C>
Long-term obligations, less current maturities...................               $   582
Stockholders' equity:
  Preferred Stock, $.01 par value, 1,000,000 shares authorized,
     no shares outstanding(1)....................................                    --
  Common Stock, $.01 par value, 20,000,000 shares authorized;
     5,000,000 shares outstanding, pro forma; 7,100,000 shares
     outstanding, pro forma as adjusted(1).......................                    71
  Additional paid-in capital.....................................                20,465
  Retained earnings..............................................                   926
                                                                             ----------
     Total stockholders' equity..................................                21,462
                                                                             ----------
     Total capitalization........................................               $22,044
                                                                             ----------
                                                                             ----------
</TABLE>
------------------
(1) Healthworld changed its authorized capital stock on August 13, 1997 to
    21,000,000 shares consisting of 1,000,000 shares of preferred stock, $.01
    par value per share, and 20,000,000 shares of Common Stock, $.01 par value
    per share. See 'Description of Capital Stock.'
 

                                       14
<PAGE>
               SELECTED PRO FORMA COMBINED FINANCIAL INFORMATION
 
     The following selected pro forma combined financial information gives
effect to the Consolidation, among other events, as more fully described in 'The
Consolidation,' and should be read in conjunction with the Company's unaudited
Pro Forma Combining Financial Statements and notes thereto, the Combined
Financial Statements of GHB&M and notes thereto, the Consolidated Financial
Statements of Milton and notes thereto, and 'Management's Discussion and
Analysis of Financial Condition and Results of Operations' contained elsewhere
in this Prospectus. The Consolidation will be accounted for as a pooling of
interests. The selected pro forma combined statement of income data for the
years ended December 31, 1994, 1995 and 1996 and for the six months ended June
30, 1996 and 1997 and the selected pro forma combined balance sheet data as of
December 31, 1995 and 1996 and June 30, 1997 are derived from the Company's
unaudited Pro Forma Combining Financial Statements included elsewhere herein.
The selected pro forma combined statement of income data for the years ended
December 31, 1992 and 1993, and the selected pro forma combined balance sheet
data as of December 31, 1992, 1993 and 1994, is derived from the Company's
unaudited Pro Forma Combining Financial Statements not included herein. In the
opinion of management, all such financial data includes all adjustments
(consisting of normal recurring adjustments) necessary for a fair presentation
of such data. Such financial data covers periods when GHB&M and Milton were not
under common control or management and may not be indicative of results that
would have been reported had the Consolidation and the other pro forma
adjustments occurred nor may it be indicative of the Company's future financial
or operating results.
 
<TABLE>
<CAPTION>
                                                                                                  SIX MONTHS ENDED
                                                            YEAR ENDED DECEMBER 31,                   JUNE 30,
                                                -----------------------------------------------   -----------------
                                                 1992      1993      1994      1995      1996      1996      1997
                                                -------   -------   -------   -------   -------   -------   -------
                                                               (IN THOUSANDS, EXCEPT PER SHARE DATA)
<S>                                             <C>       <C>       <C>       <C>       <C>       <C>       <C>
STATEMENT OF INCOME DATA:
Revenues......................................  $10,569   $11,206   $13,081   $16,767   $24,209   $11,322   $14,783
                                                -------   -------   -------   -------   -------   -------   -------
Operating expenses:
Salaries and related costs....................    6,876     7,554     7,890     9,422    15,392     7,525    10,400
Other operating expenses......................    2,596     3,321     3,727     4,904     5,615     2,797     3,000
                                                -------   -------   -------   -------   -------   -------   -------
                                                  9,472    10,875    11,617    14,326    21,007    10,322    13,400
                                                -------   -------   -------   -------   -------   -------   -------
Income from operations........................    1,097       331     1,464     2,441     3,202     1,000     1,383
Interest expense, net.........................        7         8        14         2        69       (48)      (21)
                                                -------   -------   -------   -------   -------   -------   -------
Income before provision for income taxes......    1,090       323     1,450     2,439     3,133     1,048     1,404
Provision for income taxes(1).................      436       106       613     1,038     1,305       425       584
                                                -------   -------   -------   -------   -------   -------   -------

Net income....................................  $   654   $   217   $   837   $ 1,401   $ 1,828   $   623   $   820
                                                -------   -------   -------   -------   -------   -------   -------
                                                -------   -------   -------   -------   -------   -------   -------
Earnings per share............................  $  0.13   $  0.04   $  0.17   $  0.28   $  0.37   $  0.12   $  0.16
                                                -------   -------   -------   -------   -------   -------   -------
                                                -------   -------   -------   -------   -------   -------   -------
Shares used in computing earnings
  per share...................................    5,000     5,000     5,000     5,000     5,000     5,000     5,000
</TABLE>
 
<TABLE>
<CAPTION>
                                                                   DECEMBER 31,
                                                ---------------------------------------------------
                                                 1992       1993       1994       1995       1996      JUNE 30, 1997
                                                -------    -------    -------    -------    -------    -------------
                                                                           (IN THOUSANDS)
<S>                                             <C>        <C>        <C>        <C>        <C>        <C>
BALANCE SHEET DATA:
Working capital..............................   $ 2,450    $ 1,835    $ 1,904    $ 3,904    $ 4,132       $    48
Total assets.................................    11,327     13,792     13,848     18,703     22,597        19,916
Long-term debt, including current portion....     1,216        838        662      1,223      1,419         1,324
Stockholders' equity.........................     3,501      2,914      3,880      7,339      8,576         5,557
</TABLE>
------------------
(1) Immediately upon the consummation of the Consolidation, the status of the
    companies comprising GHB&M as S Corporations under the Code will terminate.
    The pro forma provision for income taxes reflects a provision for federal
    income taxes as if each of such entities were a C Corporation rather than an
    S Corporation for such periods. See 'The Consolidation.'
 
                                       15
<PAGE>
                 SELECTED FINANCIAL INFORMATION OF GHB&M AND MILTON
 
     The following selected financial information for each of GHB&M and Milton
should be read in conjunction with the Combined Financial Statements of GHB&M
and the notes thereto, the Consolidated Financial Statements of Milton and the
notes thereto, and 'Management's Discussion and Analysis of Financial Condition
and Results of Operations' contained elsewhere in this Prospectus. The selected
combined statement of income data of GHB&M for the years ended December 31,
1994, 1995, 1996 and the selected combined balance sheet data as of December 31,
1995 and 1996 are derived from GHB&M's audited Combined Financial Statements
which are included elsewhere herein. The selected combined statement of income
data of GHB&M for the years ended December 31, 1992 and 1993 and the selected
combined balance sheet data as of December 31, 1992, 1993 and 1994 are derived
from GHB&M's unaudited Combined Financial Statements not included herein, and in
the opinion of management, include all adjustments necessary for a fair
presentation of such data. The selected combined statement of income data of
GHB&M for the six months ended June 30, 1996 and 1997 and the selected combined
balance sheet data as of June 30, 1997 are derived from GHB&M's unaudited
Combined Financial Statements included elsewhere herein which, in the opinion of
management, include all adjustments (consisting of normal recurring adjustments)
necessary for a fair presentation of the combined financial position and results

of operations of GHB&M. The selected consolidated statement of income data of
Milton for the years ended November 30, 1994, 1995 and 1996 and the selected
consolidated balance sheet data as of November 30, 1995 and 1996 are derived
from Milton's audited Consolidated Financial Statements, which are included
elsewhere herein. The selected consolidated statement of income data of Milton
for the years ended November 30, 1992 and 1993 and the selected consolidated
balance sheet data as of November 30, 1992, 1993 and 1994 are derived from
Milton's audited Consolidated Financial Statements not included herein, and in
the opinion of management include all adjustments necessary for a fair
presentation of such data. The selected consolidated statement of income data of
Milton for the seven months ended June 30, 1996 and 1997 and the selected
consolidated balance sheet data as of June 30, 1997 are derived from Milton's
unaudited Consolidated Financial Statements included elsewhere herein which, in
the opinion of management, include all adjustments (consisting of normal
recurring adjustments) necessary for a fair presentation of the consolidated
financial position and results of operations of Milton. The results of
operations of GHB&M for the six months, and of Milton for the seven months,
ended June 30, 1997 are not necessarily indicative of the results for the full
fiscal year.

<TABLE>
<CAPTION>
                                                                     GHB&M
                             -------------------------------------------------------------------------------------
                                                                (IN THOUSANDS)
                                                                                        SIX MONTHS ENDED
                                         YEAR ENDED DECEMBER 31,                            JUNE 30,
                             -----------------------------------------------   -----------------------------------
                              1992      1993      1994      1995      1996           1996               1997
                             -------   -------   -------   -------   -------   ----------------   ----------------
<S>                          <C>       <C>       <C>       <C>       <C>       <C>                <C>
STATEMENT OF INCOME DATA:
Revenues...................  $ 9,036   $ 9,234   $10,415   $12,368   $14,314       $  6,383           $  7,459
Income from operations.....      991        16     1,088     1,927     2,183            378                991
Net income.................      927        11     1,067     1,816     2,049            423              1,006
</TABLE>

<TABLE>
<CAPTION>
                                                                   DECEMBER 31,
                                                ---------------------------------------------------
                                                 1992       1993       1994       1995       1996      JUNE 30, 1997
                                                -------    -------    -------    -------    -------    -------------
<S>                                             <C>        <C>        <C>        <C>        <C>        <C>
BALANCE SHEET DATA:
Working capital..............................   $ 2,606    $ 1,974    $ 2,455    $ 4,061    $ 4,668       $ 4,680
Total assets.................................    10,264     11,190     12,232     13,287     14,049        14,180
Long-term debt, including current portion....       875        785        587         82        223           176
</TABLE>
 
<TABLE>
<CAPTION>
                                                                                MILTON
                                               -------------------------------------------------------------------------
                                                                            (IN THOUSANDS)
                                                                                                   SEVEN MONTHS ENDED
                                                           YEAR ENDED NOVEMBER 30,                      JUNE 30,
                                               -----------------------------------------------   -----------------------
                                                1992      1993      1994      1995      1996      1996         1997
                                               -------   -------   -------   -------   -------   -------   -------------
<S>                                            <C>       <C>       <C>       <C>       <C>       <C>       <C>
STATEMENT OF INCOME DATA:
Revenues.....................................  $ 1,533   $ 1,972   $ 2,666   $ 4,399   $ 9,895   $ 5,434      $ 8,147
Income from operations.......................      106       315       390       558     1,085       575          308
Net income...................................       64       230       222       316       502       257           29
</TABLE>
 
<TABLE>
<CAPTION>
                                                                   NOVEMBER 30,
                                                ---------------------------------------------------
                                                 1992       1993       1994       1995       1996      JUNE 30, 1997
                                                -------    -------    -------    -------    -------    -------------
<S>                                             <C>        <C>        <C>        <C>        <C>        <C>
BALANCE SHEET DATA:
Working capital..............................   $  (145)   $  (140)   $   (64)   $  (157)   $  (536)      $(1,132)
Total assets.................................     1,063      2,602      1,681      3,401      6,487         7,300
Long-term debt, including current portion....        92         53         75      1,141      1,196         1,148
</TABLE>
 
                                       16
<PAGE>
                    MANAGEMENT'S DISCUSSION AND ANALYSIS OF
                 FINANCIAL CONDITION AND RESULTS OF OPERATIONS
 
     The following discussion should be read in conjunction with the Company's
unaudited Pro Forma Combining Financial Statements and notes thereto, the
Combined Financial Statements of GHB&M and notes thereto and the Consolidated
Financial Statements of Milton and notes thereto appearing elsewhere herein.

INTRODUCTION
 
     Healthworld has conducted no operations to date and was formed to acquire
all of the outstanding capital stock of GHB&M and Milton in the Consolidation
concurrently with the consummation of the Offering. For a discussion of the
Consolidation and other related events, including the S Corporation
Distributions, see 'The Consolidation.'
 
     The Company conducts all of its operations through GHB&M and Milton. GHB&M,
which is based in New York City, is comprised of the following affiliated
entities: (i) Girgenti, Hughes, Butler & McDowell, Inc. ('GH'), founded in 1986,
which through (x) its GHB&M Division, has been providing traditional advertising
and promotion services and public relations services since 1986, (y) Rubin
Ehrenthal & Associates, a division acquired through a merger with GH in 1991,
specializes in DTC campaigns, and (z) its Data Health Division, organized in
March 1996, provides database marketing services; (ii) Medical Education
Technologies, Inc., organized in 1986, which provides medical education
services; (iii) Syberactive, organized in January 1996, which provides
interactive multimedia services; (iv) Brand Research Corporation, organized in
1992, which provides marketing research services; and (v) Black Cat Graphics,
Inc., organized in 1986, which creates graphic designs and artwork for
advertising and promotion campaigns.
 
     Milton, which is based in the United Kingdom, is comprised of the following
subsidiaries: (i) Milton Marketing Limited ('Milton Marketing'), organized in
1978, which provides traditional advertising and promotion services and
specializes in switching pharmaceutical products from prescription to 'over-the-
counter' status; (ii) Milton Headcount Limited ('Headcount'), originally formed
as a division of Milton Marketing in January 1994, which, along with Effective
Sales Personnel Limited ('ESP'), acquired in November 1995, provides contract
sales services; (iii) Milton Cater Limited ('Milton Cater'), organized in April
1996, which provides public relations services; and (iv) PDM Communications
Limited ('PDM'), acquired in November 1996, which provides direct marketing
services.
 
     The following discussion relating to the pro forma combined historical
financial results of the Company covers periods prior to the Consolidation when
GHB&M and Milton were not under common control or management and, therefore, may
not be indicative of results that would have been reported had the Consolidation
and other pro forma adjustments occurred. Accordingly, the results of operations
for the Company discussed below may not be indicative of future financial or
operating results.
 
GENERAL
 
     The Company is retained by its clients on assignments ranging in duration
from several months to several years. The Company offers a comprehensive range
of integrated services throughout a product's life-cycle, from the development
stage (pre-regulatory approval) to product launch and continuing through the
post-launch stage and, if applicable, such product's switch from prescription to
over-the-counter status.
 
     The Company derives its revenues from fees generated from providing its
communications and contract sales services to its clients. Substantially all

revenues from creative fees are recognized when earned either under monthly
retainer agreements or on an actual time incurred basis. Fees for production are
earned when the production materials are completed. Advance production billings
represent project costs and fees that are billed to clients as projects
progress, and are recognized at completion. Income for field marketing support
is recognized as services are provided. In limited circumstances, the Company
derives revenues through commissions on media and production costs.
 
     Milton operates only in the United Kingdom and, as a result, the Company is
susceptible to foreign exchange rate fluctuations between the British Pound
Sterling and the U.S. Dollar. The Company's financial statements are denominated
in U.S. Dollars, and accordingly, changes in the exchange rate between the
British
 
                                       17
<PAGE>
Pound Sterling and the U.S. Dollar will affect the translation of Milton's
financial results into U.S. Dollars for purposes of reporting the Company's
consolidated financial results.
 
RESULTS OF OPERATIONS-THE COMPANY
 
     The Company has provided communications services since 1978 and contract
sales services since January 1994. A significant portion of the Company's growth
in recent years is attributable to the expansion of the Company's contract sales
operations. The following table sets forth pro forma combined revenues for the
Company's communications and contract sales services.
 
<TABLE>
<CAPTION>
                                                                                      SIX MONTHS ENDED
                                                       YEAR ENDED DECEMBER 31,            JUNE 30,
                                                    -----------------------------    ------------------
                                                     1994       1995       1996       1996       1997
                                                    -------    -------    -------    -------    -------
                                                                      (IN THOUSANDS)
<S>                                                 <C>        <C>        <C>        <C>        <C>
Communications services revenues.................   $12,948    $15,464    $17,632    $ 8,033    $ 8,756
Contract sales services revenues.................       133      1,303      6,577      3,289      6,027
                                                    -------    -------    -------    -------    -------
  Total..........................................   $13,081    $16,767    $24,209    $11,322    $14,783
                                                    -------    -------    -------    -------    -------
                                                    -------    -------    -------    -------    -------
</TABLE>
 
     The following table set forth certain pro forma combined income statement
data of the Company expressed as a percentage of revenues for the periods
indicated.
 
<TABLE>
<CAPTION>
                                                                                        SIX MONTHS
                                                                                           ENDED
                                                         YEAR ENDED DECEMBER 31,         JUNE 30,

                                                        -------------------------     ---------------
                                                        1994      1995      1996      1996      1997
                                                        -----     -----     -----     -----     -----
<S>                                                     <C>       <C>       <C>       <C>       <C>
Revenues............................................    100.0%    100.0%    100.0%    100.0%    100.0%
Operating expenses:
  Salaries and related costs........................     60.3      56.2      63.6      66.5      70.3
  Other operating expenses..........................     28.5      29.2      23.2      24.7      20.3
                                                        -----     -----     -----     -----     -----
                                                         88.8      85.4      86.8      91.2      90.6
                                                        -----     -----     -----     -----     -----
Income from operations..............................     11.2      14.6      13.2       8.8       9.4
Interest expense, net...............................      0.1      --         0.3      (0.5)     (0.1)
                                                        -----     -----     -----     -----     -----
Income before provisions for income taxes...........     11.1      14.6      12.9       9.3       9.5
Provision for income taxes..........................      4.7       6.2       5.3       3.8       4.0
                                                        -----     -----     -----     -----     -----
Net income..........................................      6.4%      8.4%      7.6%      5.5%      5.5%
                                                        -----     -----     -----     -----     -----
                                                        -----     -----     -----     -----     -----
</TABLE>
 
SIX MONTHS ENDED JUNE 30, 1997 COMPARED TO SIX MONTHS ENDED JUNE 30, 1996
 
     Revenues for the first six months of 1997 were $14.8 million, an increase
of $3.5 million, or 30.6%, from $11.3 million for the first six months of 1996.
Of such increase, $2.7 million was attributable to the growth of the Company's
contract sales operations and the remainder was primarily attributable to the
growth of the Company's communications services in the United States, in
particular, advertising and promotion and consulting services.
 
     Salaries and related costs include all compensation and related benefits
for all employees and contracted talent. Salaries and related costs for the
first six months of 1997 were $10.4 million, an increase of $2.9 million, or
38.2%, from $7.5 million for the first six months of 1996. Salaries and related
costs represented 70.3% of revenues in the first six months of 1997, compared to
66.5% in the first six months of 1996. Such increase, as a percentage of
revenues, was primarily attributable to growth of the Company's contract sales
operations and the corresponding increase in labor costs. Generally, labor costs
associated with contract sales operations are greater as a percentage of
corresponding revenues than those for communication services.
 
     Other operating expenses primarily include occupancy, client development
and other related administrative costs. Other operating expenses for the first
six months of 1997 were $3.0 million, an increase of $203,000, or 7.3%, from
$2.8 million for the first six months of 1996. Other operating expenses
represented 20.3% of revenues in the first six months of 1997, compared to 24.7%
of revenues in the first six months of 1996. The decrease in other operating
expenses, as a percentage of revenues, was primarily attributable to such
expenses generally being fixed relative to increases in the Company's revenues.
 
                                       18
<PAGE>
     Income from operations for the first six months of 1997 was $1.4 million,

an increase of $383,000, or 38.3%, from $1.0 million for the first six months of
1996. Income from operations represented 9.4% of revenues in the first six
months of 1997, compared to 8.8% in the first six months of 1996.
 
     The provision for income taxes for the first six months of 1997 was
$584,000, an increase of $159,000, or 37.4%, from $425,000 for the first six
months of 1996. Such increase was primarily attributable to higher income before
taxes in the first six months of 1997, as compared to the first six months of
1996. The effective tax rate was 41.6% for the first six months of 1997,
compared to 40.6% for the first six months of 1996. The provision for income
taxes reflects a provision for Federal income taxes as if each of the companies
comprising GHB&M were treated as C Corporations rather than S Corporations for
such periods.
 
FISCAL 1996 COMPARED TO FISCAL 1995
 
     Revenues for 1996 were $24.2 million, an increase of $7.4 million, or
44.4%, from $16.8 million for 1995. Of such increase, $5.4 million was primarily
attributable to the internal growth of the Company's contract sales operations
as well as revenues attributable to the operations of ESP (acquired in November
1995), and the remainder was attributable to growth in the Company's
communications services, in particular, advertising and promotion, medical
education and consulting services.
 
     Salaries and related costs for 1996 were $15.4 million, an increase of $6.0
million, or 63.4%, from $9.4 million for 1995. Salaries and related costs
represented 63.6% of revenues in 1996, compared to 56.2% in 1995. Such increase,
as a percentage of revenues, was primarily attributable to the growth of the
Company's contract sales operations and the corresponding increase in labor
costs of such operations, and salaries and other costs related to the
establishment of the Company's public relations business in the United Kingdom.
 
     Other operating expenses for 1996 were $5.6 million, an increase of
$711,000, or 14.5%, from $4.9 million for 1995. Other operating expenses
represented 23.2% of revenues in 1996, compared to 29.2% in 1995. The decrease
in other operating expenses, as a percentage of revenues, was primarily
attributable to such expenses generally being fixed relative to increases in the
Company's revenues.
 
     Income from operations for 1996 was $3.2 million, an increase of $761,000,
or 31.2%, from $2.4 million for 1995. Income from operations represented 13.2%
of revenues in 1996, compared to 14.6% in 1995.
 
     The provision for income taxes for 1996 was $1.3 million, an increase of
$267,000, or 25.7%, from $1.0 million for 1995. Such increase was primarily
attributable to higher income before taxes in 1996, as compared to 1995. The
effective tax rate was 41.7% in 1996, compared to 42.6% in 1995. The provision
for income taxes reflects a provision for Federal income taxes as if each of the
companies comprising GHB&M were treated as C Corporations rather than S
Corporations for such periods.
 
FISCAL 1995 COMPARED TO FISCAL 1994
 
     Revenues for 1995 were $16.8 million, an increase of $3.7 million, or

28.2%, from $13.1 million for 1994. Of such increase, $1.2 million was
attributable to the expansion of the Company's contract sales operations, and
the remainder was attributable to growth in the Company's communications
services, in particular, advertising and promotion, medical education and
publishing services.
 
     Salaries and related costs for 1995 were $9.4 million, an increase of $1.5
million, or 19.4%, from $7.9 million for 1994. Salaries and related costs
represented 56.2% of revenues in 1995, compared to 60.3% in 1994. Salaries and
related costs, as a percentage of revenues, decreased slightly in 1995 due to
improved operating efficiencies.
 
     Other operating expenses for 1995 were $4.9 million, an increase of $1.2
million, or 31.6%, from $3.7 million for 1994. Other operating expenses, which
included additional occupancy costs in 1995, represented 29.2% of revenues in
1995, compared to 28.5% in 1994.
 
     Income from operations for 1995 was $2.4 million, an increase of $977,000,
or 66.7%, from $1.5 million for 1995. Income from operations represented 14.6%
of revenues in 1995, compared to 11.2% in 1994.
 
     The provision for income taxes for 1995 was $1.0 million, an increase of
$425,000, or 69.3%, from $613,000 for 1994. The increase was primarily
attributable to higher income before taxes in 1995, as compared to
 
                                       19
<PAGE>
1994. The effective tax rate was 42.6% in 1995, compared to 42.3% in 1994. The
provision for income taxes reflects a provision for Federal income taxes as if
each of the companies comprising GHB&M were treated as C Corporations rather
than S Corporations for such periods.
 
QUARTERLY OPERATING RESULTS
 
     The Company's results of operations have been and are expected to be
subject to quarterly fluctuations. Generally, the Company's revenues and profits
are lowest in the first quarter and highest in the fourth quarter. The Company's
quarterly revenue trends result from a number of factors including, among other
things, the timing of commencement, completion or cancellation of major projects
and industry billing practices which are tied to clients' annual marketing
budgets, while the Company's communications services expenses generally remain
constant. The Company's quarterly results may fluctuate as a result of a number
of additional factors, including delays or costs associated with acquisitions,
government regulatory initiatives and conditions in the health care industry
generally. The Company believes that because of such fluctuations, quarterly
comparisons of its financial results cannot be relied upon as an indication of
future performance.
 
     The following table sets forth, on a quarterly basis, certain pro forma
combining financial information of the Company for the 1995 and 1996 fiscal
years and for the first two quarters of the 1997 fiscal year.
 
<TABLE>
<CAPTION>

                                              1995                                     1996                           1997
                              -------------------------------------    -------------------------------------    -----------------
                                1ST       2ND       3RD       4TH        1ST       2ND       3RD       4TH        1ST       2ND
                              QUARTER   QUARTER   QUARTER   QUARTER    QUARTER   QUARTER   QUARTER   QUARTER    QUARTER   QUARTER
                              -------   -------   -------   -------    -------   -------   -------   -------    -------   -------
                                                                        (IN THOUSANDS)
<S>                           <C>       <C>       <C>       <C>        <C>       <C>       <C>       <C>        <C>       <C>
Revenues....................  $3,387    $3,910    $4,235    $5,235     $4,705    $6,100    $5,954    $7,450     $6,628    $8,155
Operating expenses:
  Salaries and related
    costs...................   2,131     2,145     2,423     2,723      3,529     3,851     3,716     4,296      5,038     5,362
  Other operating
    expenses................     810     1,147     1,434     1,513      1,372     1,481     1,436     1,326      1,397     1,603
                              -------   -------   -------   -------    -------   -------   -------   -------    -------   -------
                               2,941     3,292     3,857     4,236      4,901     5,332     5,152     5,622      6,435     6,965
                              -------   -------   -------   -------    -------   -------   -------   -------    -------   -------
Income from operations......  $  446    $  618    $  378    $  999     $ (196 )  $  768    $  802    $1,828     $  193    $1,190
                              -------   -------   -------   -------    -------   -------   -------   -------    -------   -------
                              -------   -------   -------   -------    -------   -------   -------   -------    -------   -------
</TABLE>
 
LIQUIDITY AND CAPITAL RESOURCES
 
     GHB&M's cash provided by operations for the six months ended June 30, 1997
was $936,000 and was comprised of net income of $1.0 million and a decrease in
accounts receivable of $2.1 million, partially offset by (i) an increase in
unbilled production charges of $1.8 million, and (ii) an increase in other
assets of $618,000. GHB&M's cash used in investing activities for the six months
ended June 30, 1997 was $157,000 consisting of capital expenditures. GHB&M's
cash used in financing activities for the six months ended June 30, 1997 was
$944,000 and was primarily comprised of S Corporation distributions to
stockholders of $497,000 and the repayment of bank debt of $447,000, in the
aggregate.
 
     Milton's cash used in operating activities for the seven months ended June
30, 1997 was $502,000 and was comprised of (i) an increase in accounts
receivable of $244,000, (ii) an increase in unbilled production charges of
$186,000, (iii) an increase in other current assets and other assets of
$379,000, and (iv) a net decrease in accounts payable and accrued expenses of
$93,000, partially offset by an increase in advance billings of $150,000.
Milton's cash used in investing activities for the seven months ended June 30,
1997 was $72,000, consisting of capital expenditures. Milton's cash provided by
financing activities for the seven months ended June 30, 1997 was primarily
comprised of additional bank overdraft borrowings of $805,000, partially offset
by repayment of bank loans and capital lease obligations of $140,000.
 
     Cash provided by operations of the Company on a combined basis for 1996 was
$3.4 million and primarily consisted of net income for the period of $2.6
million, a reduction in unbilled production charges of $1.6 million, and an
increase in accrued liabilities of $885,000, partially offset by an increase in
accounts receivable of $2.1 million and a reduction in accounts payable of
$394,000. Cash used in investing activities of the Company on a combined basis
for 1996 was $913,000 and was primarily attributable to capital expenditures of
$721,000, the acquisition of PDM and an additional equity interest in Milton

Marketing for an aggregate of $242,000. Cash used in financing activities of the
Company on a combined basis for 1996 was $1.4 million and was primarily
comprised of S Corporation distributions to stockholders of $1.5 million and
repayment of long-term debt and
 
                                       20
<PAGE>
capital lease obligations of $66,000, which were partially financed by net
proceeds from line of credit and bank overdraft borrowings of $109,000.
 
     GHB&M's bank borrowings from Chase Manhattan Bank, N.A. (the 'GHB&M Credit
Facility') consist of (i) an uncommitted line of credit (the 'GHB&M Line of
Credit') which expired on July 31, 1997, pursuant to which GHB&M could request
borrowings of, but the bank was not obligated to lend, up to $3.5 million, (ii)
a term note in the principal amount of $300,000 (the 'GHB&M Term Note'), and
(iii) a letter of credit in the amount of $300,000 (the 'GHB&M Letter of
Credit'). The GHB&M Credit Facility is secured by a first security interest in
GHB&M's personal property and is personally guaranteed by certain of GHB&M's
stockholders. The GHB&M Term Note, which was provided to GHB&M to finance the
construction of additional office space, had $176,000 outstanding as of June 30,
1997 and bears interest at 7.75% per annum and is payable in 36 equal monthly
installments with the last installment due February 1999. No amounts were
outstanding under the GHB&M Line of Credit as of its expiration at July 31,
1997. GHB&M is negotiating an extension of the GHB&M Credit Facility as well as
a new revolving credit facility, although no assurance can be given that an
extension will be approved or that a new revolving credit facility will be
available on acceptable terms, or at all.
 
     Milton's borrowings consist of a $672,000 overdraft facility (the 'Milton
Overdraft Facility') with The Bank of Scotland plc, which bears interest payable
at the United Kingdom base rate (7% as of June 30, 1997) plus 2% per annum (the
'Prevailing Rate'). As of June 30,1997, the bank has allowed Milton to exceed
the limit under the Milton Overdraft Facility, and Milton had an outstanding
balance of approximately $1.2 million under the facility at such time. Milton is
currently negotiating with the bank to increase the limit of such facility to
$1,245,000. In addition, as of June 30, 1997, Milton had the following
outstanding indebtedness: (i) a term loan from The Bank of Scotland plc (the
'Milton Term Loan') in the principal amount of $588,000 (of which $407,000 was
outstanding on June 30, 1997), which bears interest payable at the Prevailing
Rate with principal payable in installments of $58,000 each May and November
through November 2000; (ii) a term loan in the principal amount of $456,000 (all
of which was outstanding), which bears interest at the rate of 4% per annum,
originally issued in connection with Milton's acquisition of ESP, and under
which principal is payable in March 1998, and (iii) a term loan from National
Westminster Bank plc in the principal amount of $38,000 ($23,000 of which was
outstanding as of June 30, 1997), which bears interest at 10.5% per annum
payable in monthly installments, with the final payment due in April 1998.
 
     Immediately upon consummation of the Consolidation, the status of the
companies comprising GHB&M (other than Syberactive) as S Corporations will
terminate and GHB&M will then be subject to Federal and state income taxes at
applicable corporate rates. In connection with the termination of the S
Corporation status of such companies, GHB&M is currently negotiating to enter
into an agreement with respect to the Accounts Receivable Sale, which will

provide that GHB&M will, prior to the consummation of the Consolidation, sell
approximately $2.5 million of its accounts receivable to an unaffiliated
financial institution at a negotiated discount rate. Immediately prior to the
consummation of the Consolidation, GHB&M will make the S Corporation
Distributions to its stockholders of approximately $3.5 million in the aggregate
from existing cash balances for payment by such stockholders of income taxes due
on S Corporation earnings. See 'The Consolidation.'
 
     The Company anticipates that capital expenditures for 1997 and 1998 will
total approximately $500,000 and $1.3 million, respectively. Such expenditures
will primarily include spending associated with the expansion of the Company's
New York offices and the acquisition of additional office furniture and computer
equipment.
 
     The Company's primary capital needs after the Offering will be for (i)
funding working capital requirements and general corporate purposes, including
working capital needs which will result from the Accounts Receivable Sale to be
undertaken in connection with the S Corporation Distributions of approximately
$3.5 million, (ii) potential acquisitions, (iii) the repayment of certain
outstanding indebtedness, and (iv) capital expenditures.
 
     The Company believes that cash generated from operations, the net proceeds
received by the Company from the Offering and borrowings under the Company's
credit facilities will be sufficient to fund such capital needs for at least the
next 12 months.
 
                                       21
<PAGE>
RESULTS OF OPERATIONS--GHB&M
 
     To date, GHB&M has derived all of its revenues from providing
communications services to its clients.
 
     Revenues for the first six months of 1997 were $7.5 million, an increase of
$1.1 million, or 16.9%, from $6.4 million for the first six months of 1996. This
increase was primarily attributable to growth in GHB&M's communications
services, in particular, advertising and promotion and consulting services.
Income from operations for the first six months of 1997 was $991,000, an
increase of $613,000, or 162.2%, from $378,000 for the first six months of 1996.
Income from operations represented 13.3% of revenues in the first six months of
1997, as compared to 5.9% in the first six months of 1996. The increase in
income from operations, as a percentage of revenues, resulted from an increase
in revenues, partially offset by an increase in operating expenses.
 
     Revenues for 1996 were $14.3 million, an increase of $1.9 million, or
15.7%, from $12.4 million for 1995. This increase was attributable to growth in
GHB&M's communications services, in particular, advertising and promotion,
medical education and consulting services. Income from operations for 1996 was
$2.2 million, an increase of $256,000, or 13.3%, from $1.9 million for 1995.
Income from operations represented 15.3% of revenues in 1996, as compared to
15.6% in 1995.
 
     Revenues for 1995 were $12.4 million, an increase of $2 million, or 18.8%,
from $10.4 million for 1994. This increase was attributable to growth in GHB&M's

communications services, in particular, advertising and promotion, medical
education and publishing services. Income from operations for 1995 was $1.9
million, an increase of $839,000, or 77.1%, from $1.1 million for 1994. Income
from operations represented 15.6% of revenues in 1995, as compared to 10.4% in
1994. The increase in income from operations, as a percentage of revenues,
resulted from an increase in revenues, partially offset by an increase in
salaries and related costs.
 
RESULTS OF OPERATIONS--MILTON
 
     Revenues for the first seven months of fiscal 1997 were $8.1 million, an
increase of $2.7 million, or 49.9%, from $5.4 million for the first seven months
of 1996. Such increase was attributable to the growth of Milton's contract sales
operations, partially offset by a decline in the growth of Milton's
communications services. Income from operations for the first seven months of
1997 was $308,000, a decrease of $267,000, or 46.4%, from $575,000 for the first
seven months of 1996. Income from operations represented 3.8% of revenues for
the first seven months of 1997, compared to 10.6% in the first seven months of
1996. This decline was largely attributable to a reduction in the number of
products approved by the government for 'switching' a drug from prescription to
over-the-counter status. The Company has retained its talent pool in
anticipation of a reversal of such trend. Additionally, losses from the public
relations group added to the overall decline in income from operations. The
Company is in the process of reducing its overhead associated with public
relations to reflect current business activity.
 
     Revenues for 1996 were $9.9 million, an increase of $5.5 million, or
124.9%, from $4.4 million for 1995. Of such increase, $4.9 million was primarily
attributable to the internal growth of Milton's contract sales operations
revenues attributable to the operations of ESP (acquired by Milton in November
1995), approximately $200,000 was attributable to Milton Cater, a joint venture
formed in May 1996, and the remainder was attributable to increased revenues
from Milton's communications services. Income from operations for 1996 was $1.1
million, an increase of $527,000, or 94.4%, from $558,000 for 1995. Income from
operations represented 11.0% of revenues in 1996, compared to 12.7% in 1995.
Such decrease, as a percentage of revenues, was primarily attributable to the
growth of Milton's contract sales operations, which generally have higher labor
costs as a percentage of corresponding revenues than those for communications
services.
 
     Revenues for 1995 were $4.4 million, an increase of $1.7 million, or 65.0%,
from $2.7 million for 1994. Of such increase, approximately $1.0 million was
attributable to the expansion of Milton's contract sales operations, and
approximately $600,000 was attributable to the growth of Milton's communications
services. Income from operations for 1995 was $558,000, an increase of $168,000,
or 43.1%, from $390,000 for 1994. Income from operations represented 12.7% of
revenues in 1995, compared to 14.6% in 1994. Such decrease, as a percentage of
revenues, was primarily attributable to the growth of Milton's contract sales
operations.
 
                                       22
<PAGE>
ACCOUNTING STANDARDS
 

     In March 1997, the Financial Accounting Standards Board (the 'FASB') issued
SFAS No. 128, 'Earnings Per Share.' This statement establishes standards for
computing and presenting earnings per share ('EPS'), replacing the presentation
of currently required Primary EPS with a presentation of Basic EPS. For entities
with complex capital structures, the statement requires the dual presentation
for both Basic EPS and Diluted EPS on the face of the statement of earnings.
Under this new standard, Basic EPS is computed based on weighted average common
shares outstanding and excludes any potential dilution; Diluted EPS reflects
potential dilution from the exercise or conversion of securities into common
stock, or from other contracts to issue common stock, and is similar to the
currently required Fully Diluted EPS. SFAS No. 128 is effective for financial
statements issued for periods ending after December 15, 1997, including interim
periods, and earlier application is not permitted. The adoption by the Company
of SFAS No. 128 will have no impact on the Company's reporting of EPS.
 
     In October 1995, the FASB issued SFAS No. 123, 'Accounting for Stock Based
Compensation.' The statement encourages, but does not require, companies to
account for stock compensation awards based on their fair value at the date the
awards are granted. The resulting compensation award would be shown as an
expense on the statement of earnings. Alternatively, the statement allows for
the continued use of Accounting Principles Boards ('APB') Opinion No. 25,
'Accounting for Stock Issued to Employees,' which generally results in no
compensation cost for most fixed stock-option plans, with pro forma disclosure
of net income and earnings per share determined as if the fair value based
method had been applied in measuring compensation cost. The Company will adopt
SFAS No. 123 in fiscal 1997 by continuing to apply the provisions of APB Opinion
No. 25 while providing the required pro forma disclosures as if the fair value
method had been applied.
 
     In March 1995, the FASB issued SFAS No. 121, 'Accounting for the Impairment
of Long-Lived Assets and for Long-Lived Assets to Be Disposed of,' which is
effective for fiscal years beginning after December 15, 1995. SFAS No. 121
requires that long-lived assets be reviewed for impairment whenever events or
changes in circumstances indicate that the carrying amount of the asset in
question may not be recoverable. SFAS No. 121, which was adopted in fiscal 1996,
did not have a material impact on either GHB&M's or Milton's results of
operations, cash flows or financial position.
 
                                       23
<PAGE>
                                    BUSINESS
 
     The following presentation contains forward looking statements which
involve risks and uncertainties. The Company's actual results could differ
materially from those anticipated in these forward-looking statements as a
result of certain factors, including those set forth under 'Risk Factors' and
elsewhere in this Prospectus.
 
OVERVIEW
 
     The Company is a leading international marketing and communications
services company specializing in health care. The Company provides many of the
world's largest pharmaceutical and other health care companies with a
comprehensive range of integrated strategic marketing services designed to

accelerate the market's acceptance of new products and to sustain marketability
throughout their life-cycles. The Company's communications services include
advertising and promotion, publishing, medical education, public relations,
consulting, interactive multimedia, database marketing and marketing research
services. The Company also offers contract sales services which are delivered
through dedicated and syndicated sales teams.
 
INDUSTRY BACKGROUND
 
     Pharmaceutical and other health care companies have been increasing their
spending on advertising, marketing and other communications services. Worldwide
spending by pharmaceutical and biotechnology companies on promotional marketing
and contract sales is estimated to reach $5.9 billion in 1997 and to increase by
$1.0 billion by 1999. Additionally, $3.0 billion is spent annually on continuing
medical education. The Company believes that such growth will continue due to a
number of factors, including the following:
 
     NEED TO MAXIMIZE RETURNS ON NEW DRUGS.  In response to the increasing costs
and time required to develop and commercialize a new pharmaceutical product,
pharmaceutical companies implement marketing and communications programs to
achieve rapid market penetration for newly developed products. The cost of
developing a new clinical drug is estimated to be approximately $500 million,
and the research and development process for a new clinical drug, from the
beginning stages of research to obtaining final regulatory approval in the
United States, is estimated to take approximately 12 years. As a result, once a
pharmaceutical company is ready to begin commercial introduction of a newly
developed drug, only approximately five to eight years of patent protection may
remain. In order to recoup their costs of development, maximize sales, develop
brand acceptance and loyalty and achieve a higher market share in the shortest
time period possible, pharmaceutical companies now begin their marketing efforts
for a new drug in its development stage and, upon regulatory approval and
commercialization, continue with sophisticated large-scale advertising and
marketing campaigns.
 
     CHANGES IN THE HEALTH CARE INDUSTRY.  In response to governmental and
market pressures to reduce the cost of health care services and products while
providing such services to a greater portion of the population, the health care
industry has undergone significant changes, including the emergence of managed
care as a primary means for delivery of and payment for such services and
products. Pharmaceutical and other health care companies and providers are being
forced to deliver a greater volume of services and products at reduced costs. In
addition to justifying health care services and products on the basis of safety
and efficacy, pharmaceutical and health care companies and providers must now
also focus increasingly on economic factors and cost-efficiency with respect to
their services and products. As a result, health care companies are spending
more money on marketing and communications services to educate health care
providers, consumers and managed care companies and other third party payor
organizations as to the cost-effectiveness, as well as safety and efficacy, of
their products.
 
     GROWTH OF DIRECT-TO-CONSUMER MARKETING.  During the last five years the use
of direct-to-consumer marketing ('DTC') to promote prescription drugs to
consumers has grown rapidly. Prior to the emergence of DTC, prescription drugs
were promoted almost exclusively to physicians. In 1996, the first year in which

more money was spent on DTC to promote prescription drugs than on advertising to
physicians, pharmaceutical companies spent approximately $600 million on DTC,
which is twice as much as they spent in 1995 and almost 10 times more than in
1991. Figures for the first few months of 1997 suggest that the total may double
again and may exceed $1.0 billion for the year.
 
                                       24
<PAGE>
     The Company believes that the tremendous growth in DTC in the United States
(DTC is currently prohibited in Europe by governmental regulations) evolved in
response to the increased costs of developing and commercializing new drugs and
the changes brought about by health care reform and managed care, as well as
increased consumer awareness of, and participation in, decisions concerning
health care treatment. As a result, DTC was developed to create brand awareness
and brand loyalty among consumers and to motivate the consumer to specifically
request more information from their physician with respect to a specific brand
of drug to determine its appropriateness for their treatment. In the past, DTC
has been primarily communicated through print media due to regulations imposed
by the United States Food and Drug Administration (the 'FDA') that controlled
the content of television advertisements. In August 1997, the FDA relaxed such
regulations by allowing televised DTC campaigns to promote the benefits of
specific brand-name drugs while only displaying the major side effects and risks
of such drugs in an easily understood format, as compared to the previously
required display of complex and lengthy data. The Company believes that the
relaxation of such FDA regulations will contribute to the rapid growth of DTC,
which the Company expects will continue, and that pharmaceutical companies will
increasingly rely primarily on marketing and communications firms with
particular expertise in DTC of prescription drugs.
 
     INCREASED USE OF OUTSOURCED SALES AND MARKETING SERVICES.  Pharmaceutical
and other health care companies, in response to cost-containment pressures, are
increasingly outsourcing labor intensive, high cost services, including
marketing and sales and research functions. For example, the introduction of a
new drug requires the immediate availability of a large number of specially
trained sales personnel. As a result, pharmaceutical and other health care
companies are increasingly relying on contract sales organizations to assemble,
train and provide them with the largest possible sales force covering numerous
locations to achieve rapid market penetration and increased sales volume.
 
     NEW MEDIA.  Advances in technology are dramatically influencing the
delivery of marketing information. Recent developments in digital technology
such as CD-ROM, the World Wide Web, the Internet, laptop PC presentations and
interactive kiosks are revolutionizing the marketing industry. For example,
interactive multimedia are increasingly being used for patient and physician
education, sales force training and public relations. The Company believes that
pharmaceutical and other health care companies will continue to seek to retain
progressive marketing and communications companies that have the resources and
expertise to develop and incorporate interactive multimedia and other new
technology in their programs and campaigns.
 
     NEED FOR GLOBAL EXPERTISE.  The Company believes globalization is
developing as a result of the recent surge of multinational consolidations in
the pharmaceutical industry, increased foreign protection of intellectual
property, the development of large multi-country trading blocks which may lead

to reduced barriers to foreign commerce, and world-wide access to common
information through the development and use of new media. The Company believes
that in the future, pharmaceutical and other health care companies will seek to
retain marketing and communications firms specializing in health care that have
international reach and experience and are capable of developing multinational
campaigns, or campaigns on a region-by-region basis, with consistent concepts.
 
STRATEGY
 
     The Company's strategy is to capitalize on continued growth in marketing
and communications spending by pharmaceutical and other health care companies by
(i) maintaining and enhancing its creative excellence and technical expertise,
(ii) offering its clients a comprehensive range of integrated services, (iii)
continuing to specialize in health care, (iv) increasing its contract sales
services, and (v) further expanding globally. The Company intends to implement
its strategy through internal development and potential acquisitions.
 
     MAINTAIN AND ENHANCE CREATIVE EXCELLENCE AND TECHNICAL EXPERTISE.  The
Company seeks to recruit the best available creative talent to maintain its
creative excellence. The Company believes that its creative talent enables it to
develop new ways to effectively promote its clients' products. The Company
believes it is an industry leader in the development of DTC campaigns for
prescription drugs as well as marketing strategies and campaigns for 'switching'
a drug from prescription to over-the-counter (non-prescription) status. The
Company was one of the first firms to develop a DTC campaign for a prescription
drug and, currently, the Company has 12 DTC assignments. GHB&M, which has
consistently been recognized in the industry as one of the top health care
 
                                       25
<PAGE>
communications agencies, was named 'Agency of the Year' in 1993 and 1996 by Med
Ad News, a medical advertising and communications trade publication, and was a
finalist for such award in 1992 and 1994. GHB&M was also named 'Most Creative
Agency' by Med Ad News in 1995. In addition, the Company maintains a high level
of technological expertise and utilizes new interactive multimedia and other new
technologies in its programs and campaigns.
 
     OFFER A COMPREHENSIVE RANGE OF INTEGRATED SERVICES.  The Company believes
that its clients are continuing to expand their sales and marketing efforts and
require marketing and communications companies that can provide a comprehensive
range of integrated services. The Company's communications services include
advertising and promotion, publishing, medical education, public relations,
consulting, interactive multimedia and database marketing services. The Company
also provides contract sales and marketing research services. Through such
diversification, the Company is able to provide a specific service or cross-sell
multiple services to its clients within a fully integrated campaign. The Company
believes that it will continue to realize significant benefits by capitalizing
on available opportunities which may arise to increase the number of services it
provides.
 
     CONTINUED SPECIALIZATION IN HEALTH CARE.  The Company will continue to
focus on providing its services primarily to pharmaceutical and other health
care companies. The Company believes that its expertise in and understanding of
the business, consumer, scientific, medical and regulatory issues relating to

the health care industry are critical in developing the most effective marketing
campaigns and strategies with respect to pharmaceutical and other health care
products and services. The Company's staff includes physicians, pharmacists,
biologists and other personnel with extensive experience in providing marketing
and communications services to health care companies. The Company intends to
continue to recruit experienced health care and scientific professionals to
ensure that its knowledge base remains up to date.
 
     EXPANSION OF CONTRACT SALES SERVICES.  Pharmaceutical and other health care
companies are increasingly outsourcing certain marketing and sales services to
contract sales organizations. Currently, the Company's contract sales
organization operates only in the United Kingdom and provides its services
primarily to consumer products companies, utilities and other non-health care
related companies. In March 1997, the Company expanded its contract sales
organization in the United Kingdom to enable it to provide services to
pharmaceutical and other health care companies in order to take advantage of the
increased use by such companies in the United Kingdom of contract sales forces
to market their products. The Company intends to expand its contract sales
operations into the United States by the end of the first quarter of 1998 and
anticipates that such operations will focus almost exclusively on pharmaceutical
and other health care products. The Company believes that contract sales will
enable it to complement its existing communications services with a flexible
sales force designed to augment its clients' sales activities.
 
     EXTEND GLOBAL REACH.  The Company believes that pharmaceutical and other
health care companies will increasingly seek to retain marketing and
communications companies with international reach and experience. The Company
believes that it is positioned to address such future demand through its
operations in the United States and the United Kingdom, and through Healthworld
B.V., a world-wide network of licensed independent advertising agencies located
in 12 other countries. Through Healthworld B.V., the Company can utilize the
creative talents of proven agencies that have expertise and knowledge of
particular countries or geographic regions in order to develop consistent and
integrated multinational campaigns for its clients. The Company currently
intends to continue to expand the Healthworld B.V. network and will regularly
evaluate opportunities to expand its business into other international
locations.
 
     GROWTH THROUGH ACQUISITIONS.  The Company intends to pursue acquisitions of
marketing and communications companies specializing in health care in its
existing markets and internationally, including possibly acquiring Healthworld
B.V. licensed agencies. The Company anticipates that it will apply a portion of
the net proceeds of the Offering to undertake such acquisitions if suitable
acquisition candidates are identified. While the Company regularly evaluates and
discusses potential acquisitions, the Company currently has no understandings,
commitments or agreements with respect to any such acquisitions. See 'Risk
Factors-- Management of Growth; Acquisition Risks,' 'Use of Proceeds' and
'Management's Discussion and Analysis of Financial Condition and Results of
Operations.'
 
                                       26
<PAGE>
SERVICES
 

     The Company provides a wide array of marketing and communications services
to its clients ranging from the execution of a discrete marketing project, such
as designing product packaging, to taking responsibility for the overall
marketing message, which enables the Company to incorporate a wide variety of
its services into one integrated marketing campaign. The Company seeks to
develop brand loyalty and awareness for its clients at any stage of a product's
life-cycle and approaches each project by carefully evaluating the product, the
client's goals with respect to such product and industry and competitive
considerations.
 
     The services provided by the Company include:
 
  COMMUNICATIONS SERVICES
 
     Advertising and Promotion.  The Company's traditional advertising and
promotion services include developing creative concepts for advertising
campaigns for pharmaceutical and other health care products and applying such
creative concepts to the development and production of a wide variety of
marketing and promotional materials, including medical journal advertisements,
direct mail materials, sales force brochures, hospital displays, convention
exhibit panels, drug sample packages and reminder promotional items. Such
campaigns are targeted almost exclusively to physicians, nurses and other health
care providers and to wholesale distributors. The Company also analyzes
marketing research data, which is either developed by the Company (through
various methods including focus group studies, telephone interview studies and
mailings) or obtained from its clients and other third-party sources, to
determine the most appropriate audience to target as well as the types of
marketing and promotional materials to employ in a campaign.
 
     In response to the rapid growth of DTC during the last five years, the
Company expanded its advertising and promotion services to include DTC. The
Company believes it has become an industry leader in developing DTC campaigns
for prescription drugs, having been one of the first firms to develop such a DTC
campaign. Through a dedicated team engaged exclusively in developing DTC
campaigns, the Company believes it offers more specialized and comprehensive
services to its clients than firms which focus primarily on the promotion of
consumer products generally or on non-DTC advertising and the promotion of
pharmaceutical products.
 
     The Company also believes it is an industry leader in Europe in developing
campaigns for 'switching' a drug from prescription to over-the-counter status.
For example, in the United Kingdom, Regaine (Rogaine in the United States), a
product of Pharmacia & Upjohn, never achieved its sales expectations as a
prescription-only product despite being advertised and promoted to physicians by
other agencies. The Company believed that Regaine's lack of success was
primarily attributable to doctors' skepticism of the drug's effectiveness and a
general perception of hair loss being a cosmetic problem rather than a medical
disorder. In May 1995, the Company presented a comprehensive plan to Pharmacia &
Upjohn that included a new positioning and field marketing program emphasizing
the product's ability to stop further hair loss and relegated the regeneration
of hair to a secondary message. The Company developed and implemented an
integrated media plan which incorporated seven consumer advertisements, special
pharmacist programs (including in-store training manuals and display materials),
and a public relations launch in London.

 
     Publishing.  DTC publications are increasingly being employed as an
additional element of an integrated marketing campaign to promote disease
awareness, understanding of and compliance with treatment, and brand awareness
and loyalty. As part of a DTC campaign developed by the Company for Wyeth-Ayerst
Laboratories' drug Premarin, an estrogen replacement for menopausal women, the
Company developed and publishes Seasons, a bi-monthly magazine for women who are
on Premarin therapy, which is devoted to women's health care issues, including
issues concerning menopause and osteoporosis as well as the efficacy and
benefits of the drug and the means by which it can help improve overall quality
of life. The Company believes that the magazine's current per issue circulation
of 1.0 million Premarin patients makes it one of the most popular women's health
magazines ever published and that the Company's integrated marketing campaign
has contributed to Premarin becoming one of the world's leading drugs in terms
of prescription sales volume.
 
     The Company is seeking to expand its publishing business by offering DTC
publications to pharmaceutical companies as a marketing tool with respect to
drugs used for long term therapy for chronic conditions or illnesses such as
asthma, arthritis, ulcers, heart disease, diabetes and obesity. In addition, the
Company believes that such
 
                                       27
<PAGE>
DTC publications can be utilized by insurers and managed care companies as part
of a disease specific management program designed to educate a patient as to his
or her disease, including treatment options and lifestyle advice which may lead
to an overall reduction in the cost of treatment and care.
 
     Medical Education.  The Company develops medical educational programs
targeted primarily to health care providers that are tied closely to the
strategy and marketing goals for its clients, including continuing medical
education programs for which physicians obtain credit and are required to
complete to maintain their licenses. In addition to planning, implementing and
managing symposia, workshops and other conferences that commonly utilize a
multi-disciplinary faculty to address the full spectrum of care on featured
topics, the Company creates newsletters, articles, slide lecture kits and
posters. The Company also assists pharmaceutical and other health care companies
in developing, writing and placing journal articles and supplements, and offers
specialized training programs which incorporate new training technologies that
can be applied in selling pharmaceutical products to non-traditional purchasers,
including managed care organizations and public health officials. The Company
offers such services throughout a product's life-cycle, including prior to
regulatory approval, in order to create awareness and generate interest among
the health care community about such product prior to such approval.
 
     Public Relations.  The Company provides a broad range of public relations
services to its clients, including tactical development, media relations, crisis
management, special events, public sponsorship packages, professional and
patient association liaison, grant and fellowship initiatives, editorial
projects, graphic design and video production. The Company typically integrates
its public relations programs into its overall marketing campaign for a client.
The Company believes that its in-depth knowledge of professional trade and
consumer media and its strong media contacts provide it with ongoing

opportunities to place high impact stories publicizing client products and
services. The Company applies strict journalistic standards to all media contact
initiatives, including the development of news stories, research fact checking
and the production of press materials. In addition, the Company is responsive to
changing regulatory and business climates and works closely with the in-house
regulatory affairs departments and sales organizations of its clients.
 
     Consulting.  The Company's consulting services include strategic planning,
new product development, clinical and regulatory affairs and health economics.
Clients retain the Company to assist them in the development of strategic and
business plans. Typically, the Company investigates and studies the results of
clinical trials and marketing research studies to formulate a strategic
direction for a client's products. The Company may recommend to its clients,
among other things, conducting cost effectiveness clinical studies, extending
patent life protection through line extensions, considering various approaches
to dealing with the FDA, and developing pricing strategies and specific clinical
trials to support certain marketing objectives. The Company currently
subcontracts clinical and regulatory affairs and health economics consulting
services to independent companies specializing in such services. While the
Company is currently considering expanding to provide such regulatory affairs
and health economics consulting services 'in-house,' there can be no assurance
that the Company will, in the future, expand into such services.
 
     Interactive Multimedia.  The Company develops and incorporates interactive
multimedia and other new technologies into its programs and campaigns. The
Company has utilized virtually all existing digital formats, including laser
disc, kiosks, on-line and CD-ROM and owns an extensive archive of over 4,000
medical illustrations which it incorporates in such multimedia formats. The
Company also provides website design and updating, demographics targeting,
statistical measurement and list analysis. The Company believes that interactive
multimedia are particularly attractive to its clients because specific audiences
can be targeted. For example, the Company was retained by Sanofi Winthrop
Pharmaceuticals ('Sanofi') to create an interactive CD-ROM to educate a
specialty group of cardiologists who treat congestive heart failure with respect
to the features and benefits of Primacor. Sanofi believed that Primacor
possessed a novel mechanism of action which most physicians were unaware of or
did not understand. The Company determined that, in addition to the on-going
advertising and sales promotional efforts and the educational programs for the
brand, a CD-ROM program implemented as an educational tool would educate
physicians on the benefits of the brand. The CD-ROM program developed for
Primacor by clinicians presented specific case studies which illustrated the
broad utility and efficacy of Primacor. The interactive nature of CD-ROM allowed
physicians to gain a more comprehensive understanding of Primacor while having
an enjoyable learning experience. A study conducted by Sanofi's
 
                                       28
<PAGE>
Marketing Research Department reported that participating doctors praised the
Primacor interactive CD-ROM program as providing an important and valuable
service to the medical community.
 
     In another case, the Company was retained by Hoffmann-LaRoche Inc. to plan
and execute an integrated campaign for the launch of CellCept, a drug developed
to address the problem of organ transplant rejection. The Company's goal was to

develop an effective positioning for the brand that reflected the clinical
profile of the drug and to capture and convey information important to
physicians prescribing the drug, regardless of nationality. The Company's
involvement included naming the drug, developing a logo, conducting marketing
research to assist in creating a strategy, and developing product concepts and a
tactical plan. Since the transplant audience is relatively small and the client
lacked a presence in this closed community, the Company developed CenterSpan, a
restricted access website through which many of the major transplant centers
around the world could be linked in order to exchange data and information on
the drug. The sharing of important information through CenterSpan and the brand
positioning developed by the Company helped CellCept become one of the most
successful product launches in the history of the transplant field and made
Hoffman-La Roche a high-profile company among transplant physicians. The
CenterSpan program has been expanded and is now being run jointly by the
American Society of Transplant Physicians and the American Society of Transplant
Surgeons through a grant provided by Hoffmann-LaRoche.
 
     Database Marketing.  The Company frequently employs database technology in
developing marketing campaigns that are crafted to address a targeted audience.
The utilization by the Company of databases augments the Company's traditional
advertising and promotional services in which it analyzes marketing research
data for target audience profiling and segmentation. The Company utilizes its
own or its clients' databases as well as databases it leases from third parties
(including the American Medical Association). Through its direct marketing
division, the Company developed and manages a database of 1.5 million patients
generated from current and former patient readers per issue of Seasons. The
Company regularly evaluates other mechanisms that may enable it to collect data
to evaluate the effectiveness of its clients' marketing campaigns.
 
     Marketing Research.  The Company develops and offers its clients
specialized research programs to measure the 'return on investment' ('ROI') of
its DTC and other marketing programs. The ROI model utilized by the Company is a
proprietary model based on a consumer products research methodology that has
been adapted and modified for use with respect to prescription drugs. Through
the use of its ROI model, the Company has established normative data that it
will use as benchmarks for future ROI studies. The Company believes that data
from such programming assists the Company and its clients in determining the
most effective means of marketing a particular product.
 
  CONTRACT SALES SERVICES
 
     The Company offers a flexible range of contract sales services which are
delivered through dedicated and syndicated sales teams. The Company's contract
sales teams form a network of trained professionals that provides clients with
substantial flexibility in selecting the extent and costs of promoting products
as well as the clients' level of involvement in managing the sales effort.
Dedicated sales teams are comprised of sales representatives recruited by the
Company in accordance with client specifications to conduct sales efforts for a
particular client. Dedicated sales teams can be managed by the Company or can
report directly to the client, depending on client preference. Syndicated sales
teams promote a number of products for different clients and are generally
managed directly by the Company.
 
     The Company believes that speed of recruitment, quality of training and

management of sales representatives, supported by advanced information
technology, are key to providing clients with a sales force tailored to meet
their geographic and scheduling needs. The Company's ability to assemble a sales
team quickly is a product of combining the talents of experienced personnel for
screening and interviewing candidates with the use of information technology,
such as scanning and resume tracking systems, to expedite recruitment. The
Company believes that it can recruit client-specific national sales force in as
few as eight to 12 weeks, depending on the assignment, whereas the Company
believes pharmaceutical and other health care product companies often take six
to nine months to build an internal sales force. Sound hiring procedures,
including background screenings and drug testing programs, supplemented by the
Company's internal training and development programs, help to ensure the quality
of recruited personnel.
 
                                       29
<PAGE>
     Currently, the Company provides its contract sales services in the United
Kingdom primarily to consumer product companies, utilities and other non-health
care related companies. The Company's contract sales organization, Headcount,
currently is the fifth largest contract sales company in the United Kingdom. The
Company hires sales personnel on a project-by-project basis, with the actual
number of representatives retained contingent upon a particular assignment. The
Company maintains a database listing approximately 5,000 sales personnel, and
typically employs, either on a part-time or full-time basis, approximately 1,000
sales persons at any given time.
 
     In March 1997, the Company expanded its contract sales organization in the
United Kingdom to enable it to provide contract sales services to pharmaceutical
and other health care product companies. In addition, the Company currently
intends to begin providing contract sales services in the United States by the
end of the first quarter of 1998. The Company anticipates that its contract
sales operations in the United States will focus almost exclusively on
pharmaceutical and other health care products and services.
 
HEALTHWORLD B.V.
 
     In August 1993, the Company organized Healthworld B.V., a world-wide
network of licensed independent marketing and communications agencies, in
response to the Company's belief that pharmaceutical and other health care
companies will increasingly seek to retain marketing and communications
companies with international reach and experience. Healthworld B.V. enables the
Company to utilize the creative talents of proven agencies that have expertise
and knowledge of particular countries or geographic regions to develop
consistent and integrated multinational campaigns for its clients.
 
     Healthworld B.V. currently consists of 12 licensed independent
communications agencies (other than the Company) located in Belgium, Canada,
Denmark, Finland, France, Holland, Hungary, Italy, Norway, South Africa, Spain,
Sweden, the United Kingdom and the United States. Each member agency has entered
into a license agreement with Healthworld B.V. which provides, among other
things, that such agency will perform services for the clients of any other
member agency upon request by such other member agency.
 
     Although to date Healthworld B.V. has not contributed materially to the

Company's results of operations, the Company believes that Healthworld B.V. has
enabled the Company to attract additional clients based upon the Company's
ability to offer global reach and expertise.
 
CLIENTS
 
     The Company currently services approximately 45 clients. The Company's
clients are primarily pharmaceutical and other health care companies, including
health care service providers and manufacturers of diagnostic equipment, medical
equipment, medical devices and medical supplies. The Company's major clients
include five of the top ten pharmaceutical companies in the world today based on
global market share. The Company currently provides its contract sales services
in the United Kingdom primarily to consumer products companies, utilities and
other non-health care related companies. In 1996, the following clients of the
Company represented $300,000 or more of the Company's pro forma combined
revenues:
 
Alza Pharmaceuticals
Applied Microbiology, Inc.
Eli Lilly & Company
Forest Laboratories
The Hospital Saving Association
Johnson & Johnson Clinical Diagnostics
Kimberly-Clark Limited
Kraft Jacobs Suchard Limited
The Liposome Company
Muro Pharmaceuticals, Inc.
Ortho/McNeil Pharmaceuticals (a division of
  Johnson & Johnson)
Roche Laboratories
Sanofi Winthrop Pharmaceuticals
SmithKline Beecham Pharmaceuticals
Whitehall, Inc
Wyeth-Ayerst Laboratories
 
     Clients are not generally bound to an individual agency and may move their
accounts at any time from one agency to another. In addition, clients generally
tend to use more than one agency for their marketing requirements. The Company's
ability to compete for new advertising clients and assignments is limited by the
 
                                       30
<PAGE>
Company's general practice (and the practice followed by many advertising
agencies) of not representing more than one client with competing product lines.
 
INTELLECTUAL PROPERTY
 
     In 1997, the Company entered into a 50-year license agreement (the 'License
Agreement') with Healthworld B.V. pursuant to which Healthworld B.V. granted the
Company rights to use the 'Healthworld' and 'Healthworld Communications'
trademarks, the tradename 'Healthworld,' and the Healthworld logo, for $1.00 per
year. Under the License Agreement, Healthworld B.V. must obtain the Company's
prior written consent before further licensing such licensed property.
Healthworld B.V. has trademarks registered with the United States Patent and

Trademark Office for the words 'Healthworld' and 'Healthworld Communications'
which expire in March 2004 and for the Healthworld name together with its logo
which expires in May 2005. Healthworld B.V. also has trademarks registered or
applications for such registrations pending for the tradename 'Healthworld' and
the Healthworld logo in the United Kingdom and in each of the other countries in
which licensed Healthworld B.V. agencies are located, as well as several other
countries. The Company considers all of such United States and United Kingdom
trademarks to be material to its operations.
 
COMPETITION
 
     The health care marketing and communications industry throughout the United
States and Europe is highly competitive. The Company competes with many other
marketing and communications firms, including international and regional
full-service and specialty marketing and communications firms. Consolidation
within the pharmaceutical and health care industries as well as a trend by
pharmaceutical and health care companies to limit outsourcing of sales,
marketing and communications services to fewer organizations has heightened the
competition among such service providers for a smaller number of clients. In
addition, many of the larger consumer product marketing and communications
companies have acquired specialty health care marketing and communications
companies, which themselves have been increasingly consolidating in recent
years. For instance, each of Bozell, Jacobs, Kenyon & Eckhardt, Grey
Advertising, Interpublic Group, Omnicom Group, Inc., Saatchi & Saatchi
Advertising Affiliates Holdings, Inc. and Young & Rubicam, Inc., has one or more
divisions specializing in health care marketing and communications. Many of
these companies have substantially greater financial resources, personnel and
facilities than the Company. If the previously described consolidation trends
continue, the Company may face greater competition for its clients and for
acquisition candidates. Although the Company believes it is able to compete on
the basis of the quality of its creative product, service, reputation and
personal relationships with clients, there can be no assurance that the Company
will be able to maintain its competitive position in the industry.
 
     With respect to contract sales services provided to consumer products
companies in the United Kingdom, the Company currently competes against in-house
sales departments of such companies and contract sales organizations operating
in the United Kingdom, many of which are larger and have substantially greater
financial resources. With respect to contract sales services targeted to
pharmaceutical and medical devices, the Company currently competes in the United
Kingdom, and, if such services are expanded into the United States, will compete
in the United States, against the in-house sales departments of pharmaceutical
companies and local contract sales organizations specializing in pharmaceutical
and medical device products. The primary competitive factor affecting contract
sales and marketing services is the ability to quickly assemble, train and
manage large qualified sales forces to handle broad scale sales campaigns. The
Company believes that it competes favorably in these areas in the United Kingdom
with respect to its non-health care related contract sales services. However,
with respect to health care related contract sales services, there can be no
assurance that the Company will compete favorably in these areas in the United
Kingdom or in the United States.
 
     While there are relatively low barriers to entry into the marketing and
communications industry as a whole, the Company believes that its specific

expertise with respect to the pharmaceutical and health care industry
distinguish it from prospective competitors attempting to develop health care
communications businesses. Notwithstanding the Company's expertise, it expects
that it will face additional competition from new entrants into the industry in
the future. There can be no assurance that existing or future competitors will
not develop or offer marketing communications services and products that provide
significant performance, creative, technical or other advantages over those
offered by the Company.
 
                                       31
<PAGE>
GOVERNMENT REGULATION
 
     While there are no laws that specifically regulate the health care
communications industry, the health care and pharmaceutical industries are
generally subject to a high degree of government regulation, and the trend is
toward regulation of increasing stringency. Federal, state and local laws and
regulations affect the permissible form, content and timing of marketing
activities involving pharmaceutical and other health care products. Some of
these laws relate to general considerations such as truthfulness, comparative
advertising and the relative responsibilities of clients and advertising firms.
Other laws, such as the Food, Drug and Cosmetics Act and the anti-fraud and
abuse laws and regulations affecting the Medicare, Medicaid and other
governmental health care programs, regulate the form, content and/or timing of
marketing activities involving pharmaceutical and other health care products,
including the permissible activities the Company may undertake to develop
markets for its clients' products. The Company has implemented a rigorous review
process, emphasizing the importance of compliance with regulatory matters. In
addition, the Company's clients generally follow a rigorous internal review
process.
 
PROPERTIES
 
     The Company maintains corporate headquarters in New York in a leased
facility which occupies approximately 44,600 square feet of office space. The
lease for such office space is due to expire on December 31, 2009 and has
escalating rent currently at the base rate of $575,000 per annum which will
increase to $662,000 per annum in December 1997, $750,000 per annum in December
1998 and $970,000 per annum from December 2003 through the expiration of the
lease. The Company also leases small offices in Bellmore, New York and Chicago,
Illinois.
 
     The Company leases approximately 2,850 square feet of office space in
London for its United Kingdom headquarters and approximately 5,218 square feet
of office space in Chertsey for its contract sales operations. The Company also
leases small offices located in Brighton and in two locations in each of
Berkshire and Surrey. The aggregate annual base rent for all of the Company's
United Kingdom facilities is approximately $393,000.
 
     The Company believes that its existing facilities are adequate to meet its
current operating needs and that suitable additional space should be available
to the Company on reasonable terms should the Company require additional space
to accommodate future operations or expansion.
 

EMPLOYEES
 
     As of August 1, 1997, the Company had four part-time employees and
approximately 190 full-time employees, 110 of which were employed in the
Company's United States operations and 80 of which were employed in the
Company's United Kingdom operations, excluding sales persons employed in the
Company's contract sales organization. In the United Kingdom, the Company
typically employs approximately 1,000 sales persons for its contract sales
organization at any given time, and such sales persons are employed both on a
full-time and part-time basis. The Company is not a party to any collective
bargaining agreement and the Company's employees are not represented by any
labor union. The Company considers its relationship with its employees to be
good. The Company's success depends in large part, upon its ability to attract,
develop, motivate and retain highly skilled creative and technical employees, of
which there can be no assurance.
 
LEGAL MATTERS
 
     The Company is not a party to any pending litigation which, if decided
adversely to the Company, would have a material adverse effect on the business,
financial condition or results of operations of the Company, and the Company is
not aware of any material threatened litigation which might involve the Company.
 
                                       32
<PAGE>
                                   MANAGEMENT
 
DIRECTORS AND EXECUTIVE OFFICERS
 
     The following table sets forth information concerning the Company's
directors and executive officers and those persons who will become directors
(each, a 'Director Nominee') immediately upon consummation of the Consolidation.
 
<TABLE>
<CAPTION>
NAME                                               AGE   POSITION
------------------------------------------------   ---   ------------------------------------------------
<S>                                                <C>   <C>
Steven Girgenti.................................   51    Chairman of the Board and Chief Executive
                                                           Officer
William Leslie Milton...........................   53    Vice Chairman of the Board and President
Stuart Diamond..................................   36    Executive Vice President, Chief Financial
                                                           Officer and Secretary
William Butler..................................   52    President--Global Communications Services
Herbert Ehrenthal...............................   61    President--U.S. Communications Services
Francis Hughes..................................   59    Chief Creative Officer and Director
Michael Garnham.................................   42    Managing Director--Headcount
Peter Knight(1)(2)..............................   46    Director
Colin Lloyd(1)(2)(3)............................   55    Director
Jonah Shacknai(1)(2)(3).........................   40    Director
Alex Spizz(1)(3)................................   49    Director
</TABLE>
 
------------------

(1) Director Nominee.
 
(2) Will become a member of the Compensation Committee immediately upon
    consummation of the Consolidation.
 
(3) Will become a member of the Audit Committee immediately upon consummation of
    the Consolidation.
 
     Directors are elected annually. Each director holds office until the next
annual meeting of stockholders, or until his successor has been elected and
qualified. Executive officers are ordinarily elected annually and serve at the
discretion of the Board of Directors. See '--Employment Agreements' for a
description of certain employment agreements of executive officers.
 
     STEVEN GIRGENTI has served as Chairman of the Board and Chief Executive
Officer of the Company since August 1997. Mr. Girgenti co-founded GH in April
1986 and has served as its President and Chief Executive Officer since then.
Beginning in 1969, Mr. Girgenti worked in the pharmaceutical industry for
advertising companies specializing in medical communications, including William
Douglas McAdams. Prior to that, Mr. Girgenti held a variety of positions with
pharmaceutical companies, including Director of Marketing Research and Product
Manager for DuPont Pharmaceuticals and Manager of Commercial Development for
Bristol-Myers Squibb Company.
 
     WILLIAM LESLIE MILTON has served as Vice Chairman of the Board and
President of the Company since August 1997. Mr. Milton founded Milton Marketing
Limited in 1979 and has served as its Chairman of the Board and Chief Executive
Officer since such time. Prior to 1979, Mr. Milton held a variety of positions
with WarnerLambert Consumer Healthcare, Beecham Laboratories (South Africa),
Gillette Industries UK Limited, and Parke Davis Pty (South Africa) where he
developed an expertise in marketing management with respect to medical and
consumer health care products.
 
     STUART DIAMOND has served as Executive Vice President, Chief Financial
Officer and Secretary of the Company since August 1997. Mr. Diamond was the Vice
President-Controller of the Licensing Division of Calvin Klein Inc., an apparel
company, from April 1996 to August 1997. He was the Vice President and Chief
Financial Officer of Fenway Partners Inc., a leveraged buyout firm, from April
1995 to April 1996. Mr. Diamond was the Senior Vice President and Chief
Financial Officer of Medicis Pharmaceutical Corp., a publicly traded
pharmaceutical company, from 1990 to April 1995.
 
                                       33
<PAGE>
     WILLIAM BUTLER will become President of the Company's Global Communications
Services upon consummation of the Consolidation. Mr. Butler has been President
and Chief Operating Officer of the GHB&M Division of GH. Mr. Butler co-founded
GH in April 1986 and has served as its Executive Vice President since such time.
Mr. Butler has worked for various medical communications firms, including Sudler
& Hennessey and William Douglas McAdams. Prior to that time, Mr. Butler worked
in a number of marketing positions at Pfizer Inc. and Continental Group.
 
     HERBERT EHRENTHAL will become President of the Company's U.S.
Communications Services upon consummation of the Consolidation. Mr. Ehrenthal

has been President and Chief Operating Officer of Rubin Ehrenthal & Associates,
a division of GH, since 1991 when Rubin, Reid, Noto & Ehrenthal, Inc. ('Rubin
Ehrenthal') (of which he was a founding member) merged with GH. Prior to his
employment with Rubin Ehrenthal, Mr. Ehrenthal held a variety of senior
management positions with various advertising agencies, including BBDO Worldwide
Inc. and Ted Bates.
 
     FRANCIS HUGHES has been a director of the Company since August 1997 and
will become Chief Creative Officer of the Company upon consummation of the
Consolidation. Mr. Hughes co-founded GH in April 1986 and has served as its
Secretary since then. In 1980, Mr. Hughes co-founded William J. Bologna
International, Inc., a health care communications company. Prior to that time,
Mr. Hughes worked in the medical divisions of various advertising companies,
including J. Walter Thompson Co., Compton and William Douglas McAdams.
 
     MICHAEL GARNHAM has been the Managing Director of Headcount since August
1993. Prior to August 1993, Mr. Garnham was the Associate Director of FMCG Field
Marketing Ltd., a field marketing company.
 
     PETER KNIGHT will become a director of the Company upon consummation of the
Consolidation. Mr. Knight has been a partner of the law firm of Wunder, Knight,
Levine, Thelen & Forsey since 1991. He was General Counsel and Secretary of
Medicis Pharmaceutical Corp. from 1989 to 1991. Mr. Knight is currently a
director of Comsat Corp., an international telecommunications and network
service company, Medicis Pharmaceutical Corp. and Whitman Education Group Inc.,
a private for-profit education company.
 
     COLIN LLOYD will become a director of the Company upon consummation of the
Consolidation. Mr. Lloyd has been the Chief Executive Officer of Direct
Marketing Association (U.K.) Ltd., a direct marketing trade association, since
September 1993. Mr. Lloyd served as a consultant to and a director of various
companies from 1992 to 1993, and was President of Marketing Services Worldwide
of Roux, Seguile, Cyzak & Goudard, SA ('RSCG'), an international advertising
group, from February 1990 to August 1991. In 1969, Mr. Lloyd co-founded KLP
Group plc ('KLP'), a sales promotion and marketing services company in the
United Kingdom in which he served as the Chief Executive Officer until August
1991. KLP was acquired in 1990 by RSCG.
 
     JONAH SHACKNAI will become a director of the Company upon consummation of
the Consolidation. Mr. Shacknai has been Chairman of the Board and Chief
Executive Officer of Medicis Pharmaceutical Corp. since 1988. From 1982 to 1988,
Mr. Shacknai was a senior partner in the law firm of Royer, Shacknai, and Mehle,
where he represented over 34 multinational pharmaceutical and medical device
companies. From 1983 to 1986, Mr. Shacknai was also an executive officer of Key
Pharmaceutical, Inc., prior to its acquisition by Schering-Plough Corp. From
1977 to 1982, Mr. Shacknai served as Chief Aide to a United States House of
Representatives committee with responsibility for health policy. Mr. Shacknai
serves as a member of the National Arthritis and Musculoskeletal and Skin
Diseases Advisory Council of the National Institute of Health, and the
U.S.-Israel Science and Technology Commission.
 
     ALEX SPIZZ will become a director of the Company upon consummation of the
Consolidation. For more than the past five years, Mr. Spizz has been a senior
member of the law firm of Todtman, Young, Nachamie, Hendler & Spizz, P.C.,

counsel to the Company, GHB&M and Healthworld B.V. in connection with the
Consolidation and other corporate matters.
 
COMMITTEES OF THE BOARD
 
     Upon consummation of the Offering, the Board of Directors will establish an
Executive Committee, Compensation Committee and Audit Committee. The Executive
Committee will be entrusted with the authority to exercise the powers of the
Board of Directors between meetings of the Board of Directors. The Compensation
Committee will review and recommend to the Board of Directors the compensation
and benefits of all officers of
 
                                       34
<PAGE>
the Company, review general policy matters relating to compensation and benefits
of employees of the Company and administer the issuance of stock options to the
Company's officers, employees, directors and consultants. The Audit Committee
will be responsible for recommending annually to the Board of Directors the
independent auditors to be retained by the Company, and will meet with
management and the Company's independent auditors to determine the adequacy of
internal controls and other financial reporting matters.
 
EXECUTIVE COMPENSATION
 
     Healthworld, which was incorporated on September 12, 1996 and has conducted
limited operations and generated no revenues to date, did not pay any
compensation to its executive officers in 1996. The following table sets forth
the cash compensation paid by GHB&M for the fiscal year ended December 31, 1996,
and by Milton for the fiscal year ended November 30, 1996, to the Chief
Executive Officers of each of GHB&M and Milton, respectively, and to each of the
four other most highly compensated executive officers of GHB&M and Milton whose
cash compensation exceeded $100,000 for such respective fiscal years.
 
                           SUMMARY COMPENSATION TABLE
 
<TABLE>
<CAPTION>
                                                                  ANNUAL COMPENSATION
                                                         -------------------------------------
                                                                                OTHER ANNUAL          ALL OTHER
NAME AND PRINCIPAL POSITION                              SALARY($)   BONUS($)  COMPENSATION($)     COMPENSATION($)
-------------------------------------------------------  -------     -------   ---------------     ---------------
<S>                                                      <C>         <C>       <C>                 <C>
Steven Girgenti
  Chairman of the Board and
  Chief Executive Officer..............................    --          --         $ 337,000(1)        $ 981,500(2)
William Leslie Milton
  Vice Chairman of the Board and President.............  $98,280(3)(4)   --       $  32,340(3)(5)       --
William Butler
  President--Global Communications Services............    --          --         $ 275,000(1)        $ 222,622(2)
Herbert Ehrenthal
  President--U.S. Communications Services..............    --          --         $ 275,000(1)        $ 231,211(2)
Francis Hughes
  Chief Creative Officer...............................    --          --         $ 225,000(1)        $  52,372(2)

Michael Garnham
  Managing Director--Headcount.........................  $92,301(3)    --           --                $  45,864(3)(6)
</TABLE>
 
------------------
(1) Represents consulting fees paid by certain of the companies comprising GHB&M
    to certain companies wholly-owned by each respective officer.
 
(2) Represents distributions made to such individuals by certain of the
    companies comprising GHB&M. A portion of such distributions were made to
    cover each individual's 1995 and estimated 1996 tax liabilities associated
    with the election of the companies comprising GHB&M to be treated as S
    Corporations (other than Syberactive, which was treated as a C Corporation)
    during such periods.
 
(3) Calculated using the 1996 average exchange rate of $1.56 = pounds 1.00.
 
(4) Compensation paid by Milton Marketing.
 
(5) Includes (i) a $15,600 contribution by Milton Marketing to Mr. Milton's
    pension plan, and (ii) an aggregate of $10,952 for automobile expenses.
 
(6) Represents a cash distribution by one of the companies comprising Milton.
 
COMPENSATION COMMITTEE INTERLOCKS AND INSIDER PARTICIPATION
 
     Compensation policies and decisions, including those relating to salary,
bonuses and benefits of executive officers, have been set or made by Mr.
Girgenti, with respect to GHB&M, and Mr. Milton, with respect to Milton, since
the formation of such companies. Upon consummation of the Offering, the Board of
Directors of the Company will establish a Compensation Committee which will,
among other things, recommend to the Board of Directors the compensation to be
paid to the Company's officers. See '--Committees of the Board.'
 
                                       35
<PAGE>
EMPLOYMENT AGREEMENTS
 
     The Company will enter into a three-year employment agreement with each of
Messrs. Girgenti, Milton, Butler, Ehrenthal, Hughes and Garnham (the 'Executive
Employment Agreements'), which will provide that Messrs. Girgenti, Milton,
Butler, Ehrenthal, Hughes and Garnham (the 'Executives') will serve as the
Company's Chairman of the Board and Chief Executive Officer, Vice Chairman of
the Board and President, President--Global Communications Services,
President--U.S. Communications Services, Chief Creative Officer and Managing
Director--Headcount, respectively, at an annual salary of $360,000, $325,000,
$300,000, $300,000, $225,000 and $175,000, respectively, subject to annual
review and increase at the discretion of the Board of Directors of the Company.
Each Executive Employment Agreement is automatically renewable after the initial
three-year term for successive one year periods unless either the Company or the
Executive notifies the other at least 30 days prior to the expiration of any
term of its or his desire to terminate the agreement. Each Executive Employment
Agreement will also contain a confidentiality provision as well as a
noncompetition provision which will prohibit the Executive from competing with

the Company during the term of the applicable agreement and for a two year
period after the expiration of such term. Under Mr. Girgenti's Executive
Employment Agreement, in the event that the Company terminates Mr. Girgenti
without cause (as defined in the agreement) prior to the expiration of the
agreement, the Company will be obligated to pay Mr. Girgenti severance in an
amount equal to twice his then current base salary.
 
     Furthermore, each Executive Employment Agreement (other than Mr. Hughes'
agreement) will provide that Messrs. Girgenti, Milton, Butler, Ehrenthal and
Garnham will be entitled to a bonus based on achieving or exceeding certain
profits and revenue performance goals set by the Company during the term of
their respective employment agreement. Mr. Ehrenthal's agreement will also
provide that he will be entitled to a two year consulting arrangement, at the
end of his employment term, for $120,000 per annum.
 
     In August 1997, the Company entered into a three-year employment agreement
with Stuart Diamond (the 'Diamond Employment Agreement'), which provides that
Mr. Diamond will serve as the Company's Executive Vice President and Chief
Financial Officer at an annual base salary of $175,000, subject to annual review
and increase at the discretion of the Board of Directors of the Company. The
Diamond Employment Agreement also provides that Mr. Diamond will receive a
minimum bonus of $30,000 for the year ending December 31, 1997 and may be
entitled to additional annual bonuses as determined by the Board of Directors in
its sole discretion. The Diamond Employment Agreement is automatically renewable
after the initial three-year term for successive one year periods unless either
the Company or Mr. Diamond notifies the other at least 30 days prior to the
expiration of any term of its or his desire to terminate the agreement. The
Diamond Employment Agreement contains a confidentiality provision as well as a
non-competition provision which prohibits Mr. Diamond from competing with the
Company during the term of the agreement. Under the Diamond Employment
Agreement, the Company will be obligated to pay Mr. Diamond severance in an
amount equal to (i) six months base salary, in the event that the Company
terminates Mr. Diamond without cause (as defined in the agreement) prior to or
subsequent to the expiration of the agreement, and (ii) a minimum of three
months base salary (subject to increase at the discretion of the Board of
Directors) in the event that the Company is sold or a change of control in the
Company occurs.
 
STOCK OPTION PLAN
 
     Prior to the date of this Prospectus, the Board of Directors will adopt,
and the stockholders will approve, the Company's 1997 Stock Option Plan ('Stock
Option Plan'). The Stock Option Plan will provide for the grant of (i) options
that are intended to qualify as incentive stock options ('Incentive Stock
Options') within the meaning of Section 422 of the Code to certain employees
(including officers and directors who are employees) and (ii) options not
intended to so qualify to the Company's employees, officers, directors and
consultants. The total number of shares of Common Stock for which options may be
granted under the Stock Option Plan will be 710,000. To date, no stock options
have been granted under the Stock Option Plan. On the effective date of the
Offering, the Company will grant options under the Stock Option Plan to purchase
up to an aggregate of        shares of Common Stock at an exercise price per
share equal to the initial public offering price.
 

     The Stock Option Plan will be administered by the Compensation Committee,
which, under such plan, must be comprised of two or more non-employee directors
who will determine the terms of options to be granted under such plan, including
the exercise price, the number of shares subject to the option and the terms and
conditions of exercise. No option granted under the Stock Option Plan will be
transferable by the optionee other than by will or
 
                                       36
<PAGE>
the laws of descent and distribution and each option will be exercisable during
the lifetime of the optionee only by such optionee.
 
     The exercise price of all stock options granted under the Stock Option Plan
must be at least equal to the fair market value of such shares on the date of
grant. With respect to any participant who owns stock possessing more than 10%
of the voting rights of the Company's outstanding capital stock, the exercise
price of any Incentive Stock Option must be not less than 110% of the fair
market value on the date of grant. The term of each option granted pursuant to
the Stock Option Plan will be established by the Compensation Committee in its
sole discretion; provided, however, that the maximum term of each Incentive
Stock Option granted pursuant to the Stock Option Plan is ten years. With
respect to any Incentive Stock Option granted to a participant who owns stock
possessing more than 10% of the total combined voting power of all classes of
the Company's outstanding capital stock, the maximum term is five years. Except
as otherwise provided by the Compensation Committee at the time of grant,
options shall become exercisable ratably over five years commencing on the first
anniversary of the date of grant.
 
     The Stock Option Plan also will provide for an automatic annual option
grant for the non-employee directors. Each non-employee director will
automatically receive an option grant for 2,500 shares of Common Stock on the
effective date of the Offering and on the date of each annual meeting of
stockholders thereafter. In addition, a non-employee director who becomes a
director subsequent to the effective date of the Offering and other than on the
date of any annual meeting of stockholders will receive an option grant for
2,500 shares of Common Stock on the date he or she becomes a director. Each
grant will be at an exercise price per share equal to the market price of the
Common Stock on the grant date, will become fully exercisable on the first
anniversary of the date of grant, and will have a term of ten years measured
from the grant date, subject to earlier termination if an optionee's service as
a Board member is terminated for cause.
 
COMPENSATION OF DIRECTORS
 
     Each non-employee member of the Board of Directors will receive an annual
fee of $2,000 plus reimbursement of expenses incurred in attending meetings.
Additionally, each non-employee member of the Board of Directors will
automatically receive option grants, as provided in the Stock Option Plan. See
'Stock Option Plan.'
 
KEY PERSON LIFE INSURANCE
 
     The Company intends to obtain $4 million and $2 million term life insurance
policies covering Mr. Girgenti and Mr. Milton, respectively. The Company will be

the sole beneficiary of such policies.
 
                                       37
<PAGE>
                 CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS
 
     Prior to the consummation of the Offering, Healthworld will enter into the
Consolidation Agreements with the stockholders of GHB&M and Milton pursuant to
which, on the effective date of the Offering, Healthworld will acquire all of
the issued and outstanding stock of each of GHB&M and Milton from the
stockholders of GHB&M and Milton in exchange for an aggregate of 5,000,000
shares of Common Stock of the Company, at which time GHB&M and Milton will
become wholly-owned subsidiaries of Healthworld. See 'The Consolidation.'
 
     Immediately prior to the consummation of the Consolidation, GHB&M will make
the S Corporation Distributions to its stockholders of approximately $3.5
million in the aggregate from existing cash balances for the payment by such
stockholders of taxes due on S Corporation earnings. See 'The Consolidations.'
 
     GHB&M has incurred indebtedness which is personally guaranteed by its
stockholders or by entities controlled by its stockholders. In particular, the
payment of all obligations under the GHB&M Credit Facility is guaranteed jointly
and severally by Messrs. Girgenti, Hughes, Butler and Ehrenthal, individually,
and by certain of the companies comprising GHB&M. At June 30, 1997, the
aggregate principal amount of indebtedness outstanding under the GHB&M Credit
Facility was $175,000. In addition, Mr. Milton has personally guaranteed
Milton's obligations under its lease for office space located in Windsor,
Berkshire. The lease expires in June 2004, and the current annual base rent
under the lease is approximately $127,000. Pursuant to the terms of the
Consolidation Agreements, the Company will use commercially reasonable efforts
to have such stockholders' personal guarantees on the balance of the
indebtedness and the obligations under the lease released within 120 days after
the consummation of the Consolidation and, in the event that the guarantee on
the indebtedness cannot be released, to repay the balance of such indebtedness
or to assume the obligations under the lease, as the case may be.
 
     In 1991, each of the companies comprising GHB&M and each of their
stockholders entered into certain stockholders' agreements. Under the
Consolidation Agreements, GHB&M and its stockholders will agree to terminate
such agreements, concurrent with the consummation of the Consolidation.
 
     Todtman, Young, Nachamie, Hendler & Spizz, P.C., of which Alex Spizz, a
Director Nominee, is a partner, represents GHB&M, Healthworld B.V. and the
Company in connection with the Consolidation and other corporate matters.
 
                                       38
<PAGE>
                             PRINCIPAL STOCKHOLDERS
 
     The following table sets forth certain information regarding the beneficial
ownership of shares of Common Stock as of the date of this Prospectus, after
giving effect to the Consolidation, for (i) each director and Director Nominee;
(ii) each person known by the Company to be the beneficial owner of more than 5%
of the outstanding shares of Common Stock; (iii) each executive officer of the

Company and (iv) all directors, Director Nominees and executive officers of the
Company as a group. Each stockholder has sole voting and investment power with
respect to the shares set forth opposite such stockholder's name. All persons
listed below have an address c/o the Company's principal executive offices in
New York.
 
<TABLE>
<CAPTION>
                                                                                        PERCENTAGE BENEFICIALLY OWNED
                                                                                     ------------------------------------
NAME                                                           NUMBER OF SHARES      BEFORE OFFERING     AFTER OFFERING
-----------------------------------------------------------   -------------------    ---------------    -----------------
<S>                                                           <C>                    <C>                <C>
Steven Girgenti............................................        2,195,925               43.9%               30.9%
William Leslie Milton......................................        1,297,330               25.9%               18.3%
Stuart Diamond.............................................         --                       --                  --
William B. Butler..........................................          485,070                9.7%                6.8%
Herbert Ehrenthal..........................................          596,505               11.9%                8.0%
Francis Hughes.............................................          172,500                3.5%                2.4%
Michael Garnham............................................          188,571                3.8%                2.7%
Peter Knight...............................................         --                       --                  --
Colin Lloyd................................................         --                       --                  --
Jonah Shacknai.............................................         --                       --                  --
Alex Spizz.................................................         --                       --                  --
All directors, Director Nominees and executive officers as
  a group (11 persons).....................................        4,935,901               98.7%               69.5%
</TABLE>
 
                                       39
<PAGE>
                          DESCRIPTION OF CAPITAL STOCK
 
     The following summary description of the Company's capital stock and
certain provisions of the Company's Certificate of Incorporation and Bylaws does
not purport to be complete and is qualified in its entirety by reference to the
Company's Certificate of Incorporation and Bylaws, copies of which have been
filed with the Securities and Exchange Commission (the 'Commission') as exhibits
to the Company's registration statement on Form S-1 (the 'Registration
Statement') of which this Prospectus forms a part.
 
GENERAL
 
     The Company's authorized capital stock consists of 20,000,000 shares of
Common Stock, par value $.01 per share, and 1,000,000 shares of preferred stock,
par value $.01 per share (the 'Preferred Stock'). After giving effect to the
Consolidation, but prior to the consummation of the Offering, the Company will
have outstanding 5,000,000 shares of Common Stock and no shares of Preferred
Stock, and will have eight holders of record of Common Stock. Upon completion of
the Offering, the Company will have outstanding 7,100,000 shares of Common Stock
(7,415,000 shares if the Underwriters' over-allotment option is exercised in
full) and no shares of Preferred Stock.
 
COMMON STOCK
 

     Holders of Common Stock are entitled to one vote for each share held of
record on each matter submitted to a vote of stockholders. Subject to the prior
rights of any series of Preferred Stock which may from time to time be
outstanding, holders of Common Stock are entitled to receive ratably, dividends
when, as and if declared by the Board of Directors out of funds legally
available therefor and, upon the liquidation, dissolution, or winding up of the
Company, are entitled to share ratably in all assets remaining after payment of
liabilities and payment of accrued dividends and liquidation preferences on the
Preferred Stock, if any. Holders of Common Stock have no preemptive rights and
have no rights to convert their Common Stock into any other securities. The
outstanding Common Stock is, and the shares of Common Stock to be issued
pursuant to the Consolidation and the Offering will be, upon payment therefor,
fully paid and nonassessable.
 
PREFERRED STOCK
 
     The Preferred Stock may be issued from time-to-time by the Board of
Directors in one or more series. Subject to the provisions of the Company's
Certificate of Incorporation and limitations prescribed by law, the Board of
Directors is expressly authorized to adopt resolutions to issue shares, to fix
the number of shares and to change the number of shares constituting any series
and to provide for or change the voting powers, designations, preferences and
relative, participating, optional or other special rights, qualifications,
limitations or restrictions thereof, including dividend rights (including
whether dividends are cumulative), dividend rates, terms of redemption
(including sinking fund provisions), redemption prices, conversion rights and
liquidation preferences of the shares constituting any series of the Preferred
Stock, in each case without any further action or vote by the stockholders. The
Company has no current plans to issue any shares of Preferred Stock.
 
     The issuance of Preferred Stock, while providing desired flexibility in
connection with possible acquisitions and other corporate purposes, could have
the effect of rendering more difficult or discouraging an attempt to obtain
control of the Company by means of a tender offer, proxy contest, merger or
otherwise, thereby protecting the continuity of the Company's management. The
issuance of shares of the Preferred Stock pursuant to the Board of Directors'
authority described above may adversely affect the rights of the holders of
Common Stock. For example, Preferred Stock issued by the Company may rank prior
to the Common Stock as to dividend rights, liquidation preference or both, may
have full or limited voting rights and may be convertible into shares of Common
Stock. Accordingly, the issuance of shares of Preferred Stock may discourage
bids for the Common Stock or may otherwise adversely affect the market price of
the Common Stock.
 
LIMITATION OF LIABILITY
 
     The Company's Certificate of Incorporation and By-laws include provisions
which eliminate the personal liability of the Company's directors and officers
for monetary damages resulting from breaches of their fiduciary duty of care
(provided that such provision does not eliminate liability for breaches of the
duty of loyalty, acts or omissions not in good faith or which involve
intentional misconduct or a knowing violation of law, violations of Section 174
of the Delaware General Corporation Law, or for any transaction from which the
director derived an

 
                                       40
<PAGE>
improper personal benefit). These provisions do not limit or eliminate the right
of the Company or any stockholder to seek non-monetary relief such as an
injunction or rescission in the event of a breach of a director's duty of care.
The Certificate of Incorporation also provides that the Company shall indemnify
its directors and officers to the fullest extent permitted by Section 145 of the
Delaware General Corporation Law, including circumstances in which
indemnification is otherwise discretionary. The Company believes that these
provisions are necessary to attract and retain qualified directors and officers.
It is the position of the Commission that indemnification for liabilities under
the Securities Act is against public policy as expressed in the Securities Act
and is, therefore, unenforceable.
 
DELAWARE ANTI-TAKEOVER LAW
 
     Under Section 203 of the Delaware General Corporation Law (the 'Delaware
anti-takeover law'), certain 'business combinations' are prohibited between a
Delaware corporation, the stock of which is generally publicly traded or held of
record by more than 2,000 stockholders, and an 'interested stockholder' of such
corporation for a three-year period following the date that such stockholder
became an interested stockholder, unless (i) the corporation has elected in its
certificate of incorporation not to be governed by the Delaware anti-takeover
law (the Company has not made such an election), (ii) the business combination
is approved by the board of directors of the corporation before the other party
to the business combination became an interested stockholder, (iii) upon
consummation of the transaction which resulted in the stockholder becoming an
interested stockholder, the interested stockholder owned at least 85% of the
voting stock of the corporation outstanding at the commencement of the
transaction (excluding voting stock owned by directors who are also officers or
held in employee benefit plans in which the employees do not have a confidential
right to tender or vote stock held by the plan), or (iv) the business
combination was approved by the board of directors of the corporation and
ratified by 66 2/3% of the voting stock which the interested stockholder did not
own. The three-year prohibition also does not apply to certain business
combinations proposed by an interested stockholder following the announcement or
notification of certain extraordinary transactions involving the corporation and
a person who had not been an interested stockholder during the previous three
years or who became an interested stockholder with the approval of a majority of
the corporation's directors. The term 'business combination' is defined
generally to include mergers or consolidations between a Delaware corporation
and an interested stockholder, transactions with an interested stockholder
involving the assets or stock of the corporation or its majority-owned
subsidiaries, and transactions which increase an interested stockholder's
percentage ownership of stock. The term 'interested stockholder' is defined
generally as those stockholders who become beneficial owners of 15% or more of a
Delaware corporation's voting stock.
 
     These provisions could delay or frustrate the removal of incumbent
directors or a change in control of the Company. The provisions also could
discourage, impede, or prevent a merger, tender offer or proxy contest, even if
such event would be favorable to the interests of stockholders.
 

TRANSFER AGENT
 
     American Stock Transfer & Trust Company is the transfer agent and registrar
for the Common Stock.
 
                                       41
<PAGE>
                        SHARES ELIGIBLE FOR FUTURE SALE
 
     Upon consummation of the Consolidation and completion of the Offering, the
Company will have outstanding 7,100,000 shares of Common Stock. All of the
2,100,000 shares of Common Stock offered hereby (plus any additional shares sold
upon exercise of the Underwriters' over-allotment option) will be freely
tradeable without restriction or further registration under the Securities Act,
except for any shares purchased by any person who is or thereby becomes an
'affiliate' of the Company, which shares will be subject to the resale
limitations contained in Rule 144 promulgated under the Securities Act as
described below. The remaining 5,000,000 shares of Common Stock which will be
issued to the stockholders of GHB&M and Milton in the Consolidation, will be
'restricted securities' within the meaning of Rule 144 under the Securities Act
and, in general, if held for at least one year, will be eligible for sale in the
public market in reliance upon and subject to the limitations of Rule 144.
 
     In general, under Rule 144 as currently in effect, a person (or persons
whose shares are aggregated), including a person who may be deemed to be an
'affiliate' of the Company as that term is defined under the Securities Act, is
entitled to sell, within any three month period, the number of shares
beneficially owned for at least one year that does not exceed the greater of (i)
one percent of the number of the then outstanding shares of Common Stock; or
(ii) the average weekly trading volume of the Common Stock during the four
calendar weeks preceding the date on which notice of the proposed sale is sent
to the Commission. Sales under Rule 144 are also subject to certain requirements
as to the manner of sale, notice and the availability of current public
information about the Company. Furthermore, a person who is deemed not to have
been an affiliate of the Company during the 90 days preceding a sale by such
person and who has beneficially owned such shares for at least two years is
entitled to sell such shares without regard to the volume, manner of sale or
notice requirement.
 
     The Company and its officers and directors and the stockholders of GHB&M
and Milton will enter into Lock-up Agreements ('Lock-up Agreements') under which
they will agree not to offer, sell or otherwise dispose of any of their shares
of Common Stock or other securities of the Company for a period of 180 days,
commencing upon the date of this Prospectus, without the prior written consent
of Unterberg Harris, other than sales or issuances by the Company pursuant to
the exercise of the Underwriters' over-allotment option or pursuant to the grant
of stock options under the Company's Stock Option Plan.
 
     The stockholders of GHB&M and Milton will, pursuant to the Consolidation
Agreements, be granted the right by the Company, commencing one year from the
effective date of the Offering, to require the Company, subject to certain
exceptions, to include their shares (up to 5,000,000 in the aggregate) in any
and all offerings in which the Company proposes to register shares of Common
Stock for its own account or for the account of others under the Securities Act,

subject to the right of any managing underwriter of any such offering to exclude
some or all of the shares for marketing reasons.
 
     Prior to the Offering, no public market for the Company's securities has
existed. Following the Offering, no predictions can be made as to the effect, if
any, of future public sales of restricted shares or the availability of
restricted shares for sale in the public market. Nevertheless, the sale or
availability for sale of substantial amounts of Common Stock in the public
market could adversely affect prevailing market prices and the ability of the
Company to raise equity capital in the future.
 
                                       42
<PAGE>
                                  UNDERWRITING
 
     Subject to the terms and conditions set forth in an underwriting agreement
(the 'Underwriting Agreement'), the Company has agreed to sell to each of the
Underwriters named below, and each of the Underwriters, for whom Unterberg
Harris and Pennsylvania Merchant Group Ltd are acting as Representatives, have
severally agreed to purchase, the respective number of shares of Common Stock
set forth opposite its name below:
 
<TABLE>
<CAPTION>
                                                                                               NUMBER
UNDERWRITER                                                                                   OF SHARES
-------------------------------------------------------------------------------------------   ---------
<S>                                                                                           <C>
Unterberg Harris...........................................................................
Pennsylvania Merchant Group Ltd............................................................
 
                                                                                              ---------
     Total.................................................................................   2,100,000
                                                                                              ---------
                                                                                              ---------
</TABLE>
 
     In the Underwriting Agreement, the several Underwriters have agreed,
subject to the terms and conditions set forth therein, to purchase all of the
shares of Common Stock offered hereby if any such shares are purchased. In the
event of a default by an Underwriter, the Underwriting Agreement provides that,
in certain circumstances, such commitments of the non-defaulting Underwriters
may be increased or the Underwriting Agreement may be terminated.
 
     The Representatives have advised the Company that the Underwriters propose
initially to offer the shares of Common Stock offered hereby to the public at
the public offering price per share set forth on the cover page of this
Prospectus and to certain dealers at such price less a concession not in excess
of $        per share. The Underwriters may allow, and such dealers may reallow,
a discount not in excess of $        per share on sales to certain other
dealers. After the public offering, the offering price, discount and reallowance
may be changed.
 
     The Company has granted the Underwriters an option, which may be exercised

within 30 days after the date of this Prospectus, to purchase up to an
additional 315,000 shares of Common Stock to cover over-allotments, if any, at
the initial public offering price, less the underwriting discount. To the extent
that the Underwriters exercise the option, each of the Underwriters will have a
firm commitment, subject to certain conditions, to purchase approximately the
same percentage of shares that the number of shares of Common Stock to be
purchased by it shown on the foregoing table bears to the total number of shares
initially offered hereby.
 
     The Company has agreed to indemnify the Underwriters against certain civil
liabilities, including liabilities under the Securities Act, or to contribute to
payments the Underwriters may be required to make in respect thereof.
 
     The Company has agreed to pay the Representatives a non-accountable expense
allowance equal to 1% of the aggregate offering price of the shares of Common
Stock offered hereby (including any shares of Common Stock purchased pursuant to
the exercise of the Underwriters' over-allotment option).
 
     In connection with the Offering, the Underwriters may purchase and sell the
Common Stock in the open market. These transactions may include (i)
over-allotment transactions, (ii) stabilizing transactions, consisting of
certain bids or purchases for the purpose of preventing or restraining a decline
in the market price of the Common Stock, and (iii) purchases to cover syndicate
short positions created in connection with the Offering. The Underwriters also
may impose a penalty bid, whereby selling concessions allowed to syndicate
members or other broker-dealers in respect of the Common Stock sold in the
Offering for their account may be reclaimed by the
 
                                       43
<PAGE>
syndicate if such shares of Common Stock are repurchased by the syndicate in
stabilizing or covering transactions. These activities may stabilize, maintain
or otherwise affect the market price of the Common Stock which may be higher
than the price that might otherwise prevail in the open market. These
transactions may be effected on The Nasdaq National Market or otherwise, and
these activities, if commenced, may be discontinued at any time.
 
     The Underwriters have informed the Company that they do not intend to
confirm sales to any accounts over which they exercise discretionary authority.
 
     The Company has applied for quotation of the Common Stock on The Nasdaq
National Market under the symbol 'HWLD.'
 
     The Company and its officers and directors and the stockholders of GHB&M
and Milton will enter into Lock-Up Agreements under which they will agree not to
offer, sell or otherwise dispose of any of their shares of Common Stock or other
securities of the Company for a period of 180 days after the date of this
Prospectus without the prior written consent of Unterberg Harris, other than
sales or issuances by the Company pursuant to the exercise of the Underwriters'
over-allotment option or pursuant to the grant of stock options under the
Company's Stock Option Plan.
 
     Prior to the Offering, there has been no public market for the Common
Stock. The initial public offering price of the Common Stock offered hereby will

be arbitrarily determined by negotiation between the Company and the
Representatives and will not necessarily be related to the Company's asset
value, net worth or other established criteria of value. In determining the
initial public offering price, the Representatives and the Company will
consider, among other things, market prices of similar securities of comparable
publicly traded companies, the financial conditions and operating information of
companies engaged in activities similar to those of the Company, the financial
condition and prospects of the Company and the general condition of the
securities market.
 
                                 LEGAL MATTERS
 
     The validity of the shares of Common Stock offered hereby will be passed
upon for the Company by Rosenman & Colin LLP, New York, New York. Certain legal
matters in connection with the sale of the shares offered hereby will be passed
upon for the Underwriters by Akin, Gump, Strauss, Hauer & Feld, L.L.P., New
York, New York.
 
                                    EXPERTS
 
     The combined financial statements of GHB&M and the consolidated financial
statements of Milton included elsewhere in this Prospectus have been audited by
Arthur Andersen LLP, independent public accountants, as indicated in their
reports with respect thereto, and are included herein in reliance upon the
authority of said firm as experts in accounting and auditing in giving said
reports.
 
                           FORWARD LOOKING STATEMENTS
 
     This Prospectus and the Registration Statement, of which this Prospectus is
a part, contain various forward-looking statements and information that are
based on management's beliefs as well as assumptions made by and information
currently available to management for the Company. Although the Company believes
that the expectations reflected in such forward-looking statements are
reasonable, no assurance can be given that such expectations will prove to have
been correct. Such statements are subject to certain risks, uncertainties and
assumptions. Should one or more of these risks or uncertainties materialize, or
should underlying assumptions prove incorrect, actual results may vary
materially from those expected. Among the key factors that may have a direct
bearing on the Company's operating results are fluctuations in the economy,
successful integration of future acquisitions and the impact of competition.
 
                                       44
<PAGE>
                             ADDITIONAL INFORMATION
 
     The Company is not subject to the reporting requirements of the Securities
Exchange Act of 1934, as amended (the 'Exchange Act'). The Company has filed
with the Commission a Registration Statement, together with exhibits thereto,
relating to the shares of Common Stock offered hereby. This Prospectus, which
constitutes a part of the Registration Statement, omits certain of the
information set forth in the Registration Statement. For further information
with respect to the Company and to the shares of Common Stock offered hereby,
reference is made to such Registration Statement. Statements contained in this

Prospectus as to the contents of any contract or other documents referred to are
not necessarily complete, and in each instance, reference is made to the copy of
such contract or other document filed as an exhibit to the Registration
Statement, each such statement being qualified in all respects by such
reference. The Registration Statement and exhibits may be inspected and copied
at the public reference section at the Commission's principal office, 450 5th
Street, N.W., Judiciary Plaza, Washington, D.C. 20549, and at the Commission's
Regional Offices located at the Northwestern Atrium Center, Suite 1400, 500 West
Madison Street, Chicago, Illinois 60661-2511, and 7 World Trade Center, 13th
Floor, New York, New York 10048. Copies may be obtained from the Commission's
principal office upon payment of the fees prescribed by the Commission. Copies
of such materials can be obtained from the Commission at Judiciary Plaza, 450
Fifth Street, N.W., Washington, D.C. 20545, at prescribed rates. In addition,
the Commission maintains a Website on the Internet that contains reports, proxy
and information statements and other information regarding registrants that file
electronically with the Commission. The address of the Commission's Website is
http://www.sec.gov.
 
     Following the Offering, the Company will be subject to the reporting and
other requirements of the Exchange Act and intends to furnish to its
stockholders annual reports containing audited financial statements and
quarterly reports containing unaudited consolidated summary financial
information for each of the first three quarters of each fiscal year.
 
                                       45

<PAGE>
                         INDEX TO FINANCIAL STATEMENTS
 
<TABLE>
<CAPTION>
                                                                                                              PAGE
                                                                                                              ----
<S>                                                                                                           <C>
HEALTHWORLD CORPORATION PRO FORMA COMBINING
Introduction to Unaudited Pro Forma Combining Financial Statements.........................................    F-2
Pro Forma Combining Balance Sheets (unaudited).............................................................    F-3
Pro Forma Combining Statements of Income (unaudited).......................................................    F-6
Notes to Unaudited Pro Forma Combining Financial Statements................................................   F-11
GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES
Report of Independent Public Accountants...................................................................   F-12
Combined Balance Sheets....................................................................................   F-13
Combined Statements of Income..............................................................................   F-14
Combined Statements of Stockholders' Equity................................................................   F-15
Combined Statements of Cash Flows..........................................................................   F-16
Notes to Combined Financial Statements.....................................................................   F-17
MILTON MARKETING GROUP LIMITED AND SUBSIDIARIES
Report of Independent Public Accountants...................................................................   F-22
Consolidated Balance Sheets................................................................................   F-23
Consolidated Statements of Income..........................................................................   F-24
Consolidated Statements of Stockholders' Equity............................................................   F-25
Consolidated Statements of Cash Flows......................................................................   F-26
Notes to Consolidated Financial Statements.................................................................   F-27
</TABLE>

 
                                      F-1



<PAGE>
                            HEALTHWORLD CORPORATION
               UNAUDITED PRO FORMA COMBINING FINANCIAL STATEMENTS
                             BASIS OF PRESENTATION
 
     The following unaudited pro forma combining financial statements give
effect to the contributions of the outstanding capital stock of Girgenti,
Hughes, Butler and McDowell, Inc. and its affiliated entities ('GHB&M') and
Milton Marketing Group Limited and its subsidiaries ('Milton') to Healthworld
Corporation (the 'Company') in exchange for an aggregate of 5,000,000 shares of
common stock of the Company (collectively, the 'Consolidation'). The
Consolidation will occur on the effective date of the Offering made by this
Prospectus and will be accounted for using the pooling of interests method of
accounting.
 
     The unaudited pro forma combining balance sheets give effect to the
Consolidation, among other events, as if each event had occurred on the date of
each respective balance sheet. The unaudited pro forma combining statements of
income give effect to the Consolidation, among other events, as if each event
had occurred at the beginning of each period presented.
 
     The pro forma adjustments are based on preliminary estimates, available
information and certain assumptions and may be revised as additional information
becomes available. The pro forma financial data does not purport to represent
what the Company's financial position or results of operations would actually
have been if such transactions in fact had occurred on the dates indicated or to
project the Company's financial position or results of operations for any future
period. Since GHB&M and Milton were not under common control or management,
historical combined results may not be comparable to, or indicative of, future
performance. The unaudited pro forma combining financial statements should be
read in conjunction with the other financial statements and notes thereto
included elsewhere in this Prospectus. For a discussion of the risk factors
associated with the Company and its business, see 'Risk Factors' included
elsewhere in this Prospectus.
 
                                      F-2

<PAGE>

                            HEALTHWORLD CORPORATION

                  UNAUDITED PRO FORMA COMBINING BALANCE SHEETS

                               DECEMBER 31, 1995
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                                                            

                                                                                           
                                                                                            PRO FORMA
                                                                       GHB&M     MILTON    ADJUSTMENTS    PRO FORMA
                                                                      -------    ------    - ---------    ---------
                                                                                             (NOTE 2)
<S>                                                                   <C>        <C>        <C>           <C>
                              ASSETS
Current assets:
  Cash and cash equivalents........................................   $   627    $  511    $     --       $ 1,138
  Accounts receivable..............................................     7,854     1,058          --         8,912
  Unbilled production charges......................................     3,060        49          --         3,109
  Other current assets.............................................       242       147          --           389
                                                                      -------    ------     -------      --------
Total current assets...............................................    11,783     1,765          --        13,548
Furniture, equipment and leasehold improvements, net...............     1,136       634          --         1,770
Goodwill, net......................................................        --       994       2,015         3,009
Other assets.......................................................       368         8          --           376
                                                                      -------    ------     -------      --------
                                                                      $13,287    $3,401     $ 2,015       $18,703
                                                                      -------    ------     -------       -------
                                                                      -------    ------     -------       -------
 
               LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:
  Line of credit...................................................   $   600    $   --      $    --      $   600
  Bank loans and overdrafts........................................        --        24           --           24
  Current portion of long-term debt................................        82       107           --          189
  Current portion of capitalized lease obligation..................        --        74           --           74
  Accounts payable.................................................     1,361       340           --        1,701
  Accrued expenses.................................................       110       936           --        1,046
  Advance billings.................................................     5,569       441           --        6,010
                                                                      -------    ------      -------       -------
Total current liabilities..........................................     7,722     1,922           --         9,644
Long-term debt.....................................................        --       882           --           882
Capitalized lease obligation.......................................        --        78           --            78
Minority interests.................................................        --        89          (89)           --
Deferred rent......................................................       642        --           --           642
Deferred income taxes..............................................       118        --           --           118
                                                                      -------    ------      -------       -------
Total liabilities..................................................     8,482     2,971          (89)       11,364
                                                                      -------    ------      -------       -------
Stockholders' equity:
  Common stock.....................................................       289        --         (239)           50
  Additional paid-in capital.......................................        --        13        2,343         2,356
  Retained earnings................................................     4,516       423           --         4,939
  Cumulative foreign currency translation adjustments..............        --        (6)          --            (6)
                                                                      -------    ------      -------       -------
Total stockholders' equity.........................................     4,805       430        2,104         7,339
                                                                      -------    ------      -------       -------
                                                                      $13,287    $3,401      $ 2,015       $18,703
                                                                      -------    ------      -------       -------
                                                                      -------    ------      -------       -------
</TABLE>
 

    The accompanying notes are an integral part of these unaudited pro forma
                        combining financial statements.

                                      F-3

<PAGE>

                            HEALTHWORLD CORPORATION

                  UNAUDITED PRO FORMA COMBINING BALANCE SHEETS

                               DECEMBER 31, 1996
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                                                            PRO FORMA
                                                                      GHB&M     MILTON    ADJUSTMENTS     PRO FORMA
                                                                      -------    ------   -----------     ---------
                                                                                            (NOTE 2)     
<S>                                                                   <C>        <C>       <C>            <C>
                              ASSETS
Current assets:
  Cash and cash equivalents........................................   $ 2,214    $   --      $    --       $ 2,214
  Accounts receivable..............................................     8,539     3,266           --        11,805
  Unbilled production charges......................................     1,477        87           --         1,564
  Other current assets.............................................       122       415           --           537
                                                                      -------    ------      -------       -------
Total current assets...............................................    12,352     3,768           --        16,120
Furniture, equipment and leasehold improvements, net...............     1,242       870           --         2,112
Goodwill, net......................................................        --     1,800        2,061         3,861
Other assets.......................................................       455        49           --           504
                                                                      -------    ------      -------       -------
                                                                      $14,049    $6,487      $ 2,061       $22,597
                                                                      -------    ------      -------       -------
                                                                      -------    ------      -------       -------
 
               LIABILITIES AND STOCKHOLDERS' EQUITY

Current liabilities:
  Bank loans and overdrafts........................................   $    --    $  406      $    --       $   406
  Current portion of long-term debt................................        98       118           --           216
  Current portion of capitalized lease obligation..................        --       125           --           125
  Accounts payable.................................................     1,327     1,144           --         2,471
  Accrued expenses.................................................       120     1,977           --         2,097
  Advance billings.................................................     5,739       534           --         6,273
                                                                      -------    ------      -------       -------
Total current liabilities..........................................     7,684     4,304           --        11,988
Long-term debt.....................................................       125       825           --           950
Capitalized lease obligation.......................................        --       128           --           128
Minority interests.................................................        --       143         (143)           --
Deferred rent......................................................       665        --           --           665
Deferred income taxes..............................................       207        --           --           207
Other liabilities..................................................        --        83           --            83

                                                                      -------    ------      -------       -------
Total liabilities..................................................     8,681     5,483         (143)       14,021
                                                                      -------    ------      -------       -------
Stockholders' equity:
  Common stock.....................................................       290        --         (240)           50
  Additional paid-in capital.......................................        --        13        2,444         2,457
  Retained earnings................................................     5,078       925           --         6,003
  Cumulative foreign currency translation adjustments..............        --        66           --            66
                                                                      -------    ------      -------       -------
Total stockholders' equity.........................................     5,368     1,004        2,204         8,576
                                                                      -------    ------      -------       -------
                                                                      $14,049    $6,487      $ 2,061       $22,597
                                                                      -------    ------    -----------     -------
                                                                      -------    ------    -----------     -------
</TABLE>
 
    The accompanying notes are an integral part of these unaudited pro forma
                        combining financial statements.

                                      F-4

<PAGE>

                            HEALTHWORLD CORPORATION

                  UNAUDITED PRO FORMA COMBINING BALANCE SHEETS

                                 JUNE 30, 1997
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>    
                                                                                           PRO FORMA 
                                                                       GHB&M     MILTON   ADJUSTMENTS    PRO FORMA
                                                                      -------    ------   -----------    ---------
                                                                                           (NOTE 2)
<S>                                                                   <C>        <C>       <C>            <C>
                              ASSETS
Current assets:
  Cash and cash equivalents........................................   $ 2,049    $   19      $(1,000)      $ 1,068
  Accounts receivable..............................................     6,477     3,510       (2,500)        7,487
  Unbilled production charges......................................     3,307       273           --         3,580
  Other current assets.............................................        71       581           --           652
                                                                      -------    ------      -------       -------
Total current assets...............................................    11,904     4,383       (3,500)       12,787
Furniture, equipment and leasehold improvements, net...............     1,203       948           --         2,151
Goodwill, net......................................................        --     1,707        1,936         3,643
Other assets.......................................................     1,073       262           --         1,335
                                                                      -------    ------      -------       -------
                                                                      $14,180    $7,300      $(1,564)      $19,916
                                                                      -------    ------      -------       -------
                                                                      -------    ------      -------       -------
 
               LIABILITIES AND STOCKHOLDERS' EQUITY

Current liabilities:
  Line of credit...................................................   $    --    $   --      $    --       $    --
  Bank loans and overdrafts........................................        --     1,211           --         1,211
  Current portion of long-term debt................................        78       595           --           673
  Current portion of capitalized lease obligation..................        --        69           --            69
  Accounts payable.................................................     1,076     1,538           --         2,614
  Accrued expenses.................................................       154     1,418           --         1,572
  Advance billings.................................................     5,916       684           --         6,600
                                                                      -------    ------      -------       -------
Total current liabilities..........................................     7,224     5,515           --        12,739
Long-term debt.....................................................        98       291           --           389
Capitalized lease obligation.......................................        --       193           --           193
Minority interests.................................................        --       268         (268)           --
Deferred rent......................................................       715        --           --           715
Deferred income taxes..............................................       266        --           --           266
Other liabilities..................................................        --        57           --            57
                                                                      -------    ------      -------       -------
Total liabilities..................................................     8,303     6,324         (268)       14,359
                                                                      -------    ------      -------       -------
Stockholders' Equity:
  Common stock.....................................................       290        --         (240)           50
  Additional paid-in capital.......................................        --        13        4,568         4,581
  Retained earnings................................................     5,587       914       (5,624)          877
  Cumulative foreign currency translation adjustments..............        --        49           --            49
                                                                      -------    ------      -------       -------
Total stockholders' equity.........................................     5,877       976       (1,296)        5,557
                                                                      -------    ------      -------       -------
                                                                      $14,180    $7,300      $(1,564)      $19,916
                                                                      -------    ------      -------       -------
                                                                      -------    ------      -------       -------
</TABLE>
 
    The accompanying notes are an integral part of these unaudited pro forma
                        combining financial statements.

                                      F-5

<PAGE>

                            HEALTHWORLD CORPORATION

               UNAUDITED PRO FORMA COMBINING STATEMENTS OF INCOME

                      FOR THE YEAR ENDED DECEMBER 31, 1994
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
<TABLE>
<CAPTION>
                                                                                           PRO FORMA
                                                                       GHB&M     MILTON    ADJUSTMENTS    PRO FORMA 
                                                                      -------    ------    -----------    ---------
                                                                                             (NOTE 3)      
<S>                                                                   <C>        <C>       <C>            <C>
Revenues...........................................................   $10,415    $2,666       $  --        $13,081

                                                                      -------    ------       -----        -------
Operating expenses:
     Salaries and related costs....................................     6,416     1,474          --          7,890
     Other operating expenses......................................     2,911       802          14          3,727
                                                                      -------    ------       -----        -------
                                                                        9,327     2,276          14         11,617
Income from operations.............................................     1,088       390         (14)         1,464
Interest expense, net..............................................         2        12          --             14
                                                                      -------    ------       -----        -------
Income before provision for income taxes and minority interests....     1,086       378         (14)         1,450
Provision for income taxes.........................................        19       117         477            613
Minority interests in net earnings of subsidiaries.................        --        39         (39)            --
                                                                      -------    ------       ------       -------
Net income.........................................................   $ 1,067    $  222       $(452)       $   837
                                                                      -------    ------       ------       -------
                                                                      -------    ------       ------       -------
Earnings per share.................................................                                        $  0.17
                                                                                                           -------
                                                                                                           -------
Shares used in computing earnings per share........................                                          5,000
                                                                                                           -------
                                                                                                           -------
</TABLE>
 
    The accompanying notes are an integral part of these unaudited pro forma
                        combining financial statements.

                                      F-6

<PAGE>

                            HEALTHWORLD CORPORATION

               UNAUDITED PRO FORMA COMBINING STATEMENTS OF INCOME

                      FOR THE YEAR ENDED DECEMBER 31, 1995
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
<TABLE>
<CAPTION>
                                                                                           PRO FORMA
                                                                       GHB&M     MILTON    ADJUSTMENTS    PRO FORMA 
                                                                      -------    ------    -----------    ---------
                                                                                             (NOTE 3)      
<S>                                                                   <C>        <C>       <C>            <C>
Revenues...........................................................   $12,368    $4,399       $  --        $16,767
                                                                      -------    ------       -----        -------
Operating expenses:
     Salaries and related costs....................................     6,891     2,531          --          9,422
     Other operating expenses......................................     3,550     1,310          44          4,904
                                                                      -------    ------       -----        -------
                                                                       10,441     3,841          44         14,326
Income from operations.............................................     1,927       558         (44)         2,441
Interest expense, net..............................................       (13)       15          --              2

                                                                      -------    ------       -----        -------
Income before provision for income taxes and minority interests....     1,940       543         (44)         2,439
Provision for income taxes.........................................       124       159         755          1,038
Minority interests in net earnings of subsidiaries.................        --        68         (68)            --
                                                                      -------    ------       -----        -------
Net income.........................................................   $ 1,816    $  316       $(731)       $ 1,401
                                                                      -------    ------       -----        -------
                                                                      -------    ------       -----        -------
Earnings per share.................................................                                        $  0.28
                                                                                                           -------
                                                                                                           -------
Shares used in computing earnings per share........................                                          5,000
                                                                                                           -------
                                                                                                           -------
</TABLE>
 
    The accompanying notes are an integral part of these unaudited pro forma
                        combining financial statements.

                                      F-7

<PAGE>

                            HEALTHWORLD CORPORATION

               UNAUDITED PRO FORMA COMBINING STATEMENTS OF INCOME

                      FOR THE YEAR ENDED DECEMBER 31, 1996
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
<TABLE>
<CAPTION>
                                                                                            
                                                                                            PRO FORMA
                                                                       GHB&M     MILTON    ADJUSTMENTS    PRO FORMA
                                                                      -------    ------    -----------    ---------
                                                                                             (NOTE 3)
<S>                                                                   <C>        <C>       <C>            <C>
Revenues...........................................................   $14,314    $9,895       $  --        $24,209
                                                                      -------    ------       -----        -------
Operating expenses:
     Salaries and related costs....................................     8,599     6,793          --         15,392
     Other operating expenses......................................     3,532     2,017          66          5,615
                                                                      -------    ------       -----        -------
                                                                       12,131     8,810          66         21,007
Income from operations.............................................     2,183     1,085         (66)         3,202
Interest expense, net..............................................       (24)       93          --             69
                                                                      -------    ------       -----        -------
Income before provision for income taxes and minority interests....     2,207       992         (66)         3,133
Provision for income taxes.........................................       158       366         781          1,305
Minority interests in net earnings of subsidiaries.................        --       124        (124)            --
                                                                      -------    ------       -----        -------
Net income.........................................................   $ 2,049    $  502       $(723)       $ 1,828
                                                                      -------    ------       ------       -------

                                                                      -------    ------       ------       -------
Earnings per share.................................................                                        $  0.37
                                                                                                           -------
                                                                                                           -------
Shares used in computing earnings per share........................                                          5,000
                                                                                                           -------
                                                                                                           -------
</TABLE>
 
    The accompanying notes are an integral part of these unaudited pro forma
                        combining financial statements.

                                      F-8

<PAGE>

                            HEALTHWORLD CORPORATION

               UNAUDITED PRO FORMA COMBINING STATEMENTS OF INCOME

                     FOR THE SIX MONTHS ENDED JUNE 30, 1996
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
<TABLE>
<CAPTION>
                                                                                            PRO FORMA
                                                                       GHB&M     MILTON    ADJUSTMENTS    PRO FORMA
                                                                      -------    ------    -----------    ---------
                                                                                             (NOTE 3)
<S>                                                                   <C>        <C>       <C>            <C>
Revenues...........................................................   $ 6,383    $4,939       $  --        $11,322
                                                                      -------    ------       -----        -------
Operating expenses:
     Salaries and related costs....................................     4,174     3,351          --          7,525
     Other operating expenses......................................     1,831       933          33          2,797
                                                                      -------    ------       -----        -------
                                                                        6,005     4,284          33         10,322
Income from operations.............................................       378       655         (33)         1,000
Interest expense, net..............................................       (78)       30          --            (48)
                                                                      -------    ------       -----        -------
Income before provision for income taxes and minority interests....       456       625         (33)         1,048
Provision for income taxes.........................................        33       231         161            425
Minority interests in net earnings of subsidiaries.................        --        69         (69)            --
                                                                      -------    ------       -----        -------
Net income.........................................................   $   423    $  325       $(125)       $   623
                                                                      -------    ------       -----        -------
                                                                      -------    ------       -----        -------
Earnings per share.................................................                                        $  0.12
                                                                                                           -------
                                                                                                           -------
Shares used in computing earnings per share........................                                          5,000
                                                                                                           -------
                                                                                                           -------
</TABLE>

 
    The accompanying notes are an integral part of these unaudited pro forma
                        combining financial statements.

                                      F-9

<PAGE>

                            HEALTHWORLD CORPORATION

               UNAUDITED PRO FORMA COMBINING STATEMENTS OF INCOME

                     FOR THE SIX MONTHS ENDED JUNE 30, 1997
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
<TABLE>
<CAPTION>
                                                                                            PRO FORMA
                                                                       GHB&M     MILTON    ADJUSTMENTS    PRO FORMA
                                                                      -------    ------    -----------    ---------
                                                                                             (NOTE 3)
<S>                                                                   <C>        <C>       <C>            <C>
Revenues...........................................................   $ 7,459    $7,324       $  --        $14,783
                                                                      -------    ------       -----        -------
Operating expenses:
     Salaries and related costs....................................     4,789     5,611          --         10,400
     Other operating expenses......................................     1,679     1,288          33          3,000
                                                                      -------    ------       -----        -------
                                                                        6,468     6,899          33         13,400
Income from operations.............................................       991       425         (33)         1,383
Interest expense, net..............................................       (79)       58          --            (21)
                                                                      -------    ------       -----        -------
Income before provision for income taxes and minority interests....     1,070       367         (33)         1,404
Provision for income taxes.........................................        64       135         385            584
Minority interests in net earnings of subsidiaries.................        --       126        (126)            --
                                                                      -------    ------       -----        -------
Net income.........................................................   $ 1,006    $  106       $(292)       $   820
                                                                      -------    ------       -----        -------
                                                                      -------    ------       -----        -------
Earnings per share.................................................                                        $  0.16
                                                                                                           -------
                                                                                                           -------
Shares used in computing earnings per share........................                                          5,000
                                                                                                           -------
                                                                                                           -------
</TABLE>
 
    The accompanying notes are an integral part of these unaudited pro forma
                        combining financial statements.

                                      F-10

<PAGE>


                            HEALTHWORLD CORPORATION

          NOTES TO UNAUDITED PRO FORMA COMBINING FINANCIAL STATEMENTS

                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
1. GENERAL
 
     Healthworld Corporation (the 'Company') was incorporated in Delaware on
September 12, 1996. The Company has conducted no operations to date and will
acquire all of the outstanding common stock of Girgenti, Hughes, Butler and
McDowell, Inc. and its affiliated entities ('GHB&M') and Milton Marketing Group
Limited and its subsidiaries ('Milton') in exchange for an aggregate of 5,000
shares of common stock of the Company (the 'Consolidation') as of the effective
date of the Offering made by this Prospectus. The Consolidation will be
accounted for using the pooling of interests method of accounting.
 
     The periods included in these unaudited pro forma combining financial
statements are as follows: GHB&M--combined balance sheets as of December 31,
1995 and 1996 and June 30, 1997, and combined income statements for the years
ended December 31, 1994, 1995 and 1996, and the six months ended June 30, 1996
and 1997; and Milton--consolidated balance sheets as of November 30, 1995 and
1996 and June 30, 1997, and consolidated income statements for the years ended
November 30, 1994, 1995 and 1996, and the six months ended June 30, 1996 and
1997.
 
2. UNAUDITED PRO FORMA BALANCE SHEET ADJUSTMENTS
 
     The following pro forma adjustments have been made to the Company's pro
forma combining balance sheets to reflect:
 
     a. the Consolidation;
 
     b. an estimated $3,500 distribution to be made to the stockholders of the
        companies comprising GHB&M (other than Syberactive, Inc.) immediately
        prior to the consummation of the Consolidation from existing cash
        balances for payment by such stockholders of income taxes on 'S'
        Corporation earnings;
 
     c. an increase in additional paid-in capital of $2,124 and a corresponding
        decrease in 'S' Corporation retained earnings of GHB&M as if the 'S'
        Corporation status of the companies comprising GHB&M was terminated on
        June 30, 1997;
 
     d. the purchase of minority interests of the companies comprising Milton
        and the goodwill resulting therefrom; and
 
     e. the sale of an estimated $2,500 of accounts receivable of GHB&M to an
        unaffiliated financial institution at a negotiated discount rate prior
        to the consummation of the Consolidation. Such sale will be undertaken
        in connection with the termination of the status of each of the
        companies comprising GHB&M as 'S' Corporations, which will occur as a
        result of and upon consummation of the Consolidation.
 

3. UNAUDITED PRO FORMA STATEMENT OF INCOME ADJUSTMENTS
 
     The following pro forma adjustments have been made to the Company's pro
forma combining statements of income to reflect:
 
     a. a provision for federal and state income taxes as if each of the
        companies comprising GHB&M were treated as 'C' Corporations rather than
        'S' Corporations for such periods; and
 
     b. the purchase of minority interests of the companies comprising Milton
        and the goodwill amortization resulting therefrom.
 
                                      F-11

<PAGE>

After the execution of definitive agreements to undertake the Consolidation
discussed in Note 9 to the combined financial statements of Girgenti, Hughes,
Butler & McDowell, Inc. and Affiliates, we expect to be in a position to render
the following audit report.
 
                                                  /s/ Arthur Andersen
                                            --------------------------------
                                                     Arthur Andersen

 
August 29, 1997

 
                    REPORT OF INDEPENDENT PUBLIC ACCOUNTANTS

 
To Girgenti, Hughes, Butler & McDowell, Inc.
and Affiliates:
 
We have audited the accompanying combined balance sheets of Girgenti, Hughes,
Butler & McDowell, Inc. (a New York corporation) and Affiliates as of December
31, 1995 and 1996, and the related combined statements of income, stockholders'
equity and cash flows for each of the three years in the period ended December
31, 1996. These financial statements are the responsibility of the Company's
management. Our responsibility is to express an opinion on these financial
statements based on our audits.
 
We conducted our audits in accordance with generally accepted auditing
standards. Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of material
misstatement. An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements. An audit also includes
assessing the accounting principles used and significant estimates made by
management, as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.
 
In our opinion, the financial statements referred to above present fairly, in
all material respects, the financial position of Girgenti, Hughes, Butler &
McDowell, Inc. and Affiliates as of December 31, 1995 and 1996, and the results
of their operations and their cash flows for each of the three years in the
period ended December 31, 1996 in conformity with generally accepted accounting
principles.
 
Melville, New York
January 24, 1997
  (except with respect to the matters
  discussed in Note 9 as to which
  the date is              , 1997)
 
                                      F-12


<PAGE>
            GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

                            COMBINED BALANCE SHEETS
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                                                     DECEMBER 31,
                                                                                  ------------------     JUNE 30,
                                                                                   1995       1996         1997
                                                                                  -------    -------    -----------
                                                                                                        (UNAUDITED)
<S>                                                                               <C>        <C>        <C>
                                    ASSETS
Current assets:
  Cash and cash equivalents....................................................   $   627    $ 2,214      $ 2,049
  Accounts receivable..........................................................     7,854      8,539        6,477
  Unbilled production charges, at cost.........................................     3,060      1,477        3,307
  Other current assets.........................................................       242        122           71
                                                                                  -------    -------      -------
Total current assets...........................................................    11,783     12,352       11,904
Furniture, equipment and leasehold improvements, net...........................     1,136      1,242        1,203
Other assets...................................................................       368        455        1,073
                                                                                  -------    -------      -------
                                                                                  $13,287    $14,049      $14,180
                                                                                  -------    -------      -------
                                                                                  -------    -------      -------
                     LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:
  Line of credit...............................................................   $   600    $   400      $    --
  Current portion of long-term debt............................................        82         98           78
  Accounts payable.............................................................     1,361      1,327        1,076
  Accrued expenses.............................................................       110        120          154
  Advance production billings..................................................     5,569      5,739        5,916
                                                                                  -------    -------      -------
Total current liabilities......................................................     7,722      7,684        7,224
Commitments (Note 7)
Long-term debt.................................................................        --        125           98
Deferred rent..................................................................       642        665          715
Deferred income taxes..........................................................       118        207          266
                                                                                  -------    -------      -------
                                                                                    8,482      8,681        8,303
                                                                                  -------    -------      -------
Stockholders' equity:
  Common stock.................................................................       289        290          290
  Retained earnings............................................................     4,516      5,078        5,587
                                                                                  -------    -------      -------
Total stockholders' equity.....................................................     4,805      5,368        5,877
                                                                                  -------    -------      -------
                                                                                  $13,287    $14,049      $14,180
                                                                                  -------    -------      -------
                                                                                  -------    -------      -------
</TABLE>

 
The accompanying notes to combined financial statements are an integral part of
                             these balance sheets.

                                      F-13

<PAGE>

            GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

                         COMBINED STATEMENTS OF INCOME
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                                                                    SIX MONTHS
                                                                   YEAR ENDED DECEMBER 31,        ENDED JUNE 30,
                                                                -----------------------------    ----------------
                                                                 1994       1995       1996       1996      1997
                                                                -------    -------    -------    ------    ------
                                                                                                   (UNAUDITED)
<S>                                                             <C>        <C>        <C>        <C>       <C>
Revenues.....................................................   $10,415    $12,368    $14,314    $6,383    $7,459
                                                                -------    -------    -------    ------    ------
Operating expenses:
  Salaries and related costs.................................     6,416      6,891      8,599     4,174     4,789
  Other operating expenses...................................     2,911      3,550      3,532     1,831     1,679
                                                                -------    -------    -------    ------    ------
                                                                  9,327     10,441     12,131     6,005     6,468
Income from operations.......................................     1,088      1,927      2,183       378       991
Interest expense, net........................................         2        (13)       (24)      (78)      (79)
                                                                -------    -------    -------    ------    ------
Income before provision for income taxes.....................     1,086      1,940      2,207       456     1,070
Provision for income taxes...................................        19        124        158        33        64
                                                                -------    -------    -------    ------    ------
Net income...................................................   $ 1,067    $ 1,816    $ 2,049    $  423    $1,006
                                                                -------    -------    -------    ------    ------
                                                                -------    -------    -------    ------    ------
</TABLE>
 
The accompanying notes to combined financial statements are an integral part of
                               these statements.

                                      F-14

<PAGE>

            GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

                  COMBINED STATEMENTS OF STOCKHOLDERS' EQUITY
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>

                                                                                                COMMON    RETAINED
                                                                                                STOCK     EARNINGS
                                                                                                ------    --------
<S>                                                                                             <C>       <C>
Balance, December 31, 1993...................................................................    $289      $2,386
  Net income.................................................................................      --       1,067
  Stockholders' distributions................................................................      --        (544)
                                                                                                ------     ------
Balance, December 31, 1994...................................................................     289       2,909
  Net income.................................................................................      --       1,816
  Stockholders' distributions................................................................      --        (209)
                                                                                                ------     ------
Balance, December 31, 1995...................................................................     289       4,516
  Net income.................................................................................      --       2,049
  Stockholders' distributions................................................................      --      (1,487)
  Issuance of common stock in new affiliate..................................................       1          --
                                                                                                ------     ------
Balance, December 31, 1996...................................................................     290       5,078
  Net income (unaudited).....................................................................      --       1,006
  Stockholders' distributions (unaudited)....................................................      --        (497)
                                                                                                ------     ------
Balance, June 30, 1997 (unaudited)...........................................................    $290      $5,587
                                                                                                ------     ------
                                                                                                ------     ------
</TABLE>
 
The accompanying notes to combined financial statements are an integral part of
                               these statements.

                                      F-15

<PAGE>

            GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

                       COMBINED STATEMENTS OF CASH FLOWS
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                                                                   SIX MONTHS
                                                                   YEAR ENDED DECEMBER 31,       ENDED JUNE 30,
                                                                   ------------------------     ----------------
                                                                    1994     1995     1996       1996      1997
                                                                   ------   ------   ------     ------    ------
                                                                                                  (UNAUDITED)
<S>                                                                <C>      <C>      <C>        <C>       <C>
Cash flows from operating activities:
  Net income.....................................................  $1,067   $1,816   $2,049     $  423    $1,006
     Adjustments to reconcile net income to net cash provided by
     operating activities:
       Depreciation and amortization.............................     214      274      402        174       196
       Deferred rent.............................................      80      200       23         12        50
       Deferred income taxes.....................................      --       83       89         33        59

     Changes in operating assets and liabilities:
       Accounts receivable.......................................  (1,652)     336     (685)       703     2,062
       Unbilled production charges...............................     287     (719)   1,583        555    (1,830)
       Other current assets......................................      18      (88)     120       (108)       51
       Other assets..............................................      95       30      (88)       (34)     (618)
       Accounts payable..........................................    (145)     253      (35)      (798)     (251)
       Advanced production billing...............................   1,313   (1,653)     171         (1)      177
       Accrued expenses..........................................    (125)      98        9         10        34
                                                                   ------   ------   ------     ------    ------
Net cash provided by operating activities........................   1,152      630    3,638        969       936
                                                                   ------   ------   ------     ------    ------
Cash flows from investing activities:
  Capital expenditures, net......................................    (258)    (563)    (507)      (203)     (157)
                                                                   ------   ------   ------     ------    ------
Net cash (used in) investing activities..........................    (258)    (563)    (507)      (203)     (157)
                                                                   ------   ------   ------     ------    ------
Cash flows from financing activities:
  Distributions to stockholders..................................    (544)    (209)  (1,487)      (621)     (497)
  Net (repayment) proceeds from line of credit...................    (100)     200     (200)      (100)     (400)
  Issuance of long-term debt.....................................      --       --      300        300        --
  Repayment of long-term debt....................................     (97)    (105)    (158)       (86)      (47)
  Issuance of common stock in new affiliate......................      --       --        1          1        --
                                                                   ------   ------   ------     ------    ------
Net cash (used in) financing activities..........................    (741)    (114)  (1,544)      (506)     (944)
                                                                   ------   ------   ------     ------    ------
Net increase/(decrease) in cash and cash equivalents.............     153      (47)   1,587        260      (165)
Cash and cash equivalents at beginning of year...................     521      674      627        627     2,214
                                                                   ------   ------   ------     ------    ------
Cash and cash equivalents at end of year.........................  $  674   $  627   $2,214     $  887    $2,049
                                                                   ------   ------   ------     ------    ------
                                                                   ------   ------   ------     ------    ------
Supplemental disclosure of cash flow information:
  Cash paid for taxes............................................  $   17   $   45   $   64     $   45    $   64
                                                                   ------   ------   ------     ------    ------
                                                                   ------   ------   ------     ------    ------
  Cash paid for interest.........................................  $   30   $   31   $   41     $   31    $    8
                                                                   ------   ------   ------     ------    ------
                                                                   ------   ------   ------     ------    ------
</TABLE>
 
The accompanying notes to combined financial statements are an integral part of
                               these statements.

                                      F-16


<PAGE>

            GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

                     NOTES TO COMBINED FINANCIAL STATEMENTS
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
1. BUSINESS
 
     Girgenti, Hughes, Butler & McDowell, Inc. and Affiliates (the 'Company') is
a combined group of six affiliated companies: Girgenti, Hughes, Butler &
McDowell, Inc. ('GHB&M'); Black Cat Graphics, Inc. ('Black Cat'); Medical
Educational Technologies, Inc. ('MET'); Brand Research Corporation ('Brand');
GHBM, Inc. and Syberactive Inc. ('Syberactive'). Each of these companies is
owned in the same manner by a stockholder group consisting of four individuals.
 
     The Company provides a broad range of integrated marketing and
communications services including advertising and promotion, publishing, medical
education, public relations, consulting, interactive multimedia, database
marketing and marketing research services.
 
2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
 
  Principles of Combination
 
     The combined financial statements include the accounts of the affiliated
companies. All inter-company balances and transactions have been eliminated.
 
  Revenue Recognition
 
     Substantially all revenues are derived from fees from clients for creative
concept development, production of advertising and marketing materials and the
communication of a client's product message to target markets through the use of
educational projects.
 
     Substantially all revenues from creative fees are recognized when earned
either under monthly retainer agreements or on an actual time incurred basis.
Fees for production are earned when the production materials are completed.
Advanced production billings represent project costs and fees that are billed to
clients as projects progress, and are recognized at completion.
 
     Accounts receivable include fees recognized, project costs, and media and
production costs incurred on behalf of clients, which are paid for by the
Company and rebilled to clients.
 
  Concentration of Credit Risk
 
     The Company provides communication, marketing, advertising and related
services to a wide range of clients who operate mainly in the health care and
food service industries. For the year ended December 31, 1996, the Company had
three clients which constituted approximately 40%, 13% and 9% of total revenues.
In addition, the Company's five largest clients represent 74% of combined
revenues for that period. The Company had three clients which constituted
approximately 37%, 13% and 11% of total 1995 revenues and 24%, 17% and 9% of

total 1994 revenues. As of December 31, 1995 and 1996, primarily all of the
Company's trade accounts receivable were concentrated in companies in the health
care industry. The Company extends credit to all qualified clients, but does not
believe that it is exposed to any undue concentration of credit risk to any
significant degree. The Company maintains reserves for potential credit losses,
but has not experienced any material losses to individual clients or groups of
clients.
 
  Cash and Cash Equivalents
 
     For purposes of the combined balance sheets and combined statements of cash
flows, the Company considers all highly liquid debt instruments purchased with
original maturities of three months or less to be cash equivalents, including
commercial paper and money market mutual funds.
 
                                      F-17

<PAGE>

            GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

              NOTES TO COMBINED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES--(CONTINUED)

  Unbilled Production Charges
 
     Unbilled production charges consist principally of costs incurred in
producing advertisements and marketing communications for clients. Such amounts
are generally billed to clients when costs are incurred for radio and television
production and when print production is complete.
 
  Furniture, Equipment and Leasehold Improvements
 
     Furniture, equipment and leasehold improvements are stated at cost, net of
accumulated depreciation and amortization. Depreciation and amortization are
computed using the straight-line method over the estimated useful lives of the
assets as follows:
 
<TABLE>
<S>                                          <C>
Furniture.................................   5-7 years
Equipment.................................   5-7 years
Leasehold improvements....................   Lesser of lease term or useful life
</TABLE>
 
  Income Taxes
 
     The companies comprising the Company (other than Syberactive, which is
treated as a 'C Corporation'), with the consent of the stockholders, elected to
have their Federal and state income taxed as subchapter 'S Corporations.' In
lieu of Federal and certain state corporate income taxes, the shareholders are

taxed on their proportionate share of income, or receive the benefit of any
losses individually. New York City Corporation taxes are provided, if required,
at statutory rates.
 
  Use of Estimates
 
     The preparation of financial statements in conformity with generally
accepted accounting principles requires management to make estimates and
assumptions that affect the amounts reported in the financial statements and
accompanying notes. Actual results could differ from those estimates.
 
  New Accounting Pronouncements
 
     During 1996, the Company adopted Statement of Financial Accounting
Standards No. 121 (SFAS No. 121), 'Accounting for the Impairment of Long-Lived
Assets and Long-Lived Assets to be Disposed of.' This statement requires the
Company to review long-lived assets for impairment whenever events or changes in
circumstances indicate that the carrying amount of an asset may not be
recoverable. The effect of adoption was not material.
 
  Recently Issued Accounting Standards
 
     In March 1997, the Financial Accounting Standards Board issued Statement of
Financial Accounting Standards ('SFAS') No. 128, Earnings Per Share. This
Statement establishes standards for computing and presenting earnings per share
('EPS'), replacing the presentation of currently required primary EPS with a
presentation of Basic EPS. For entities with complex capital structures, the
statement requires the dual presentation of both Basic EPS and Diluted EPS on
the face of the statement of income. Under this new standard, Basic EPS is
computed based on weighted average shares outstanding and excludes any potential
dilution; Diluted EPS reflects potential dilution from the exercise or
conversion of securities into common stock or from other contracts to issue
common stock and is similar to the currently required fully diluted EPS. SFAS
128 is effective for financial statements issued for periods ending after
December 15, 1997, including interim periods, and earlier application is not
permitted.
 
                                      F-18

<PAGE>

            GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

              NOTES TO COMBINED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
3. FURNITURE, EQUIPMENT AND LEASEHOLD IMPROVEMENTS
 
     Furniture, equipment and leasehold improvements consist of the following:
 
<TABLE>
<CAPTION>
                                                                                                            

                                                                                                            
                                                                          DECEMBER 31,    DECEMBER 31,      JUNE 30,
                                                                              1995            1996            1997
                                                                          ------------    ------------    ------------
                                                                                                          (UNAUDITED)
<S>                                                                       <C>             <C>             <C>
     Furniture and equipment...........................................      $1,607          $2,117          $2,188
     Leasehold improvements............................................         465             465             460
                                                                             ------          ------          ------
                                                                              2,072           2,582           2,648
     Less: Accumulated depreciation and amortization...................         936           1,340           1,445
                                                                             ------          ------          ------
                                                                             $1,136          $1,242          $1,203
                                                                             ------          ------          ------
                                                                             ------          ------          ------
</TABLE>
 
     Depreciation and amortization expense of furniture, equipment and leasehold
improvements for the years ended December 31, 1994, 1995 and 1996 amounted to
approximately $214, $274 and $402, respectively, and for the six months ended
June 30, 1996 and 1997 amounted to approximately $174 and $196, respectively
(unaudited).
 
4. RESTRICTED CASH
 
     In connection with the lease for office space, the Company was required to
establish an Irrevocable Standby Letter of Credit with a face amount of $300.
The Company has set aside a Certificate of Deposit in the amount of $300 as
collateral for the Letter of Credit. The Certificate of Deposit has been
included within Other Assets due to the term of the underlying lease commitment.
 
5. BANK LOANS AND LINE OF CREDIT
 
     The Company has in place a $4,100 credit facility with a bank. The facility
currently consists of: (i) an uncommitted $3,500 line of credit ('Line of
Credit'), (ii) a $300 term note ('Term Note'), and (iii) a $300 irrevocable
letter of credit. The facility is secured by a first security interest in the
Company's personal property and a personal guarantee of several of the
stockholders of the Company. Borrowings under the facility are as follows:
 
<TABLE>
<CAPTION>
                                                                                                           
                                                                                                             
                                                                          DECEMBER 31,   DECEMBER 31,      JUNE 30,  
                                                                              1995           1996            1997
                                                                          ------------   ------------    ------------
                                                                                                         (UNAUDITED)
<S>                                                                       <C>            <C>             <C>
     Line of Credit.....................................................      $600(a)        $400(a)         $ --
     Term Note/Loan.....................................................        82(b)         223(c)          176
                                                                            ------         ------          ------
                                                                               682            623             176
 

     Less: Current portion..............................................       682            498              78
                                                                            ------         ------          ------
                                                                              $ --           $125            $ 98
                                                                            ------         ------          ------
                                                                            ------         ------          ------
</TABLE>
 
------------------
 
a) Borrowings under the Line of Credit are limited to 80% of eligible trade
   receivables, as defined in the agreement. The Line of Credit matures on July
   31, 1997 and bears interest at prime (8.25% as of December 31, 1996) plus 1%
   per annum. The Line of Credit requires the Company to maintain certain
   financial ratios. As of December 31, 1996, the Company was in compliance with
   all of the provisions of the Line of Credit.
 
b) This represented the outstanding principal balance of borrowings under a $400
   term note to finance certain leasehold improvements. The note bore interest
   at 7.5% per annum and was payable in 48 monthly installments commencing
   October 1992. As of December 31, 1996, such note had been repaid.
 
                                      F-19

<PAGE>

            GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

              NOTES TO COMBINED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
5. BANK LOANS AND LINE OF CREDIT--(CONTINUED)

c) During February 1996, the bank provided a Term Loan of $300 to finance the
   construction of additional office space. This Term Loan bears interest at
   7.75% per annum and is payable in 36 monthly installments commencing March
   1996.
 
     At December 31, 1996, maturities of debt are as follows:
 
<TABLE>
<S>                                                                  <C>
1997..............................................................   $498
1998..............................................................    106
1999..............................................................     19
</TABLE>
 
6. STOCKHOLDERS' EQUITY
 
     The financial statements are presented on a combined basis. Since there is
no parent-subsidiary relationship, there is no basis for eliminating the equity
accounts of any of the entities. As of December 31, 1995 and 1996, and as of
June 30, 1997 (unaudited), stockholders' equity consisted of the following:
 

<TABLE>
<CAPTION>
                                                                                        RETAINED EARNINGS/
                                                         COMMON STOCK                  (ACCUMULATED DEFICIT)
                                                  ---------------------------    -----------------------------------
                                        SHARES                     JUNE 30,                                JUNE 30,
COMPANY                                 ISSUED    1995    1996       1997         1995          1996        1997
-------------------------------------   ------    ----    ----    -----------    ------        ------    -----------
                                                                  (UNAUDITED)                            (UNAUDITED)
<S>                                     <C>       <C>     <C>     <C>            <C>           <C>       <C>
GHBM.................................    85.25    $192    $192       $ 192       $1,517        $1,540      $ 2,157
Black Cat............................   120.90      89      89          89        2,434         2,655        2,654
MET..................................   120.90       6       6           6          477           847          764
Brand................................   120.90       1       1           1           88            43           49
GHBM, Inc............................   120.90       1       1           1           --            (1)          --
Syberactive..........................   100.00      --       1           1           --            (6)         (37)
                                                  ----    ----    -----------    ------        ------    -----------
                                                  $289    $290       $ 290       $4,516        $5,078      $ 5,587
                                                  ----    ----    -----------    ------        ------    -----------
                                                  ----    ----    -----------    ------        ------    -----------
</TABLE>
 
7. COMMITMENTS
 
  Lease
 
     In 1994, the Company entered into a fifteen year lease for office space in
New York City. The lease is payable in monthly installments which include
certain rent holidays and escalations, which have been accounted for on a
straight-line basis over the life of the lease. As a security deposit, the
Company put in place an Irrevocable Standby Letter of Credit (see Note 4) in the
amount of $300. This amount will decrease on November 1, 1997 to $200 and to
$132 on November 1, 1998. During 1996, the Company terminated a lease agreement
on another property. The cost to terminate the lease was insignificant.
 
     The following is a schedule of the minimum annual lease payments due:
 
<TABLE>
<S>                                                                   <C>
1997...............................................................   $  608
1998...............................................................      690
1999...............................................................      750
2000...............................................................      750
2001...............................................................      750
Thereafter.........................................................    7,337
</TABLE>
 
     Total rent expense incurred for the years ended December 31, 1994, 1995 and
1996 was approximately $662, $759 and $814, respectively, and for the six months
ended June 30, 1996 and 1997 was approximately $414 and $394, respectively
(unaudited).
 
                                      F-20


<PAGE>

            GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

              NOTES TO COMBINED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
7. COMMITMENTS--(CONTINUED)

  Employment Agreements
 
     The Company has entered into employment agreements (the 'Agreements') with
certain key employees. The Agreements contain provisions for base salary and
incentives based upon certain performance measures, and are subject to
termination by either party. The aggregate annual minimum base compensation
required by the Agreements is approximately $880.
 
  Employee Benefits
 
     The Company maintains a '401 K' Plan for eligible employees, who have
completed the minimum service requirement of the plan. The Company matches up to
4% of salary for participating employees. For the years ended December 31, 1994,
1995 and 1996, the Company has contributed $64, $105 and $124, respectively, and
for the six months ended June 30, 1996 and 1997, the Company has contributed $60
and $90, respectively (unaudited), to the Plan.
 
8. INTERIM FINANCIAL STATEMENTS
 
     The combined financial statements of Girgenti, Hughes, Butler & McDowell,
Inc. as of and for the six months ended June 30, 1996 and 1997, presented herein
have been prepared by the Company without audit, pursuant to the rules and
regulations of the Securities and Exchange Commission. The financial statements
reflect all adjustments (consisting of only normal recurring adjustments) which,
in the opinion of management, are necessary to present fairly the combined
financial position, results of operations and cash flows of the Company as of
June 30, 1996 and 1997, and for the periods ended. The Company's interim results
may fluctuate as a result of a number of factors and are not necessarily
indicative of the results to be obtained for the full year.
 
9. SUBSEQUENT EVENTS
 
     Pursuant to a Letter of Intent between the Company and Milton Marketing
Group Limited and its subsidiaries ('Milton'), the Company and Milton have
agreed to cause their respective stockholders to enter into a definitive
agreement with Healthworld Corporation ('Healthworld') pursuant to which all
outstanding shares of common stock of each of the companies comprising the
Company and Milton will be exchanged for shares of Healthworld common stock as
of the effective date of the Offering (as defined below) (the 'Consolidation').
Upon consummation of the Consolidation, the entities comprising the Company
(other than Syberactive, which is already treated as a C Corporation) will no
longer be treated as S Corporations.
 
     In connection with the termination of the status of each of the companies

comprising the Company as S Corporations, the Company is currently negotiating
to enter into an agreement which will provide that the Company will, prior to
the consummation of the Consolidation, sell an estimated $2,500 of its accounts
receivable to an unaffiliated financial institution at a negotiated discount
rate. Immediately prior to the consummation of the Consolidation, the Company
will make distributions to its stockholders of approximately $3,500 in the
aggregate from existing cash balances for the payment by such stockholders of
taxes due on S Corporation earnings.
 
     Healthworld is pursuing an initial public offering of its securities (the
'Offering'). The Offering contemplates the sale of 2,100 shares of Healthworld's
common stock at an offering price between $8.00 and $9.50 per share before
underwriting commissions and Offering expenses. Healthworld plans to use the
proceeds of the Offering for working capital and general corporate purposes.
 
                                      F-21


<PAGE>
After the execution of definitive agreements to undertake the Consolidation
discussed in Note 11 to the consolidated financial statements of Milton
Marketing Group Limited and Subsidiaries, we expect to be in a position to
render the following audit report.
 
                                                  /s/ Arthur Andersen
                                              ----------------------------
                                                     Arthur Andersen
 
August 29, 1997
 

                    REPORT OF INDEPENDENT PUBLIC ACCOUNTANTS

 
To Milton Marketing Group Limited and Subsidiaries:
 
We have audited the accompanying consolidated balance sheets of Milton Marketing
Group Limited (a United Kingdom corporation, formerly known as Siteinput
Limited) and Subsidiaries as of November 30, 1995 and 1996, and the related
consolidated statements of income, stockholders' equity and cash flows for each
of the three years in the period ended November 30, 1996. These financial
statements are the responsibility of the Company's management. Our
responsibility is to express an opinion on these financial statements based on
our audits.
 
We conducted our audits in accordance with generally accepted auditing
standards. Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of material
misstatement. An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements. An audit also includes
assessing the accounting principles used and significant estimates made by
management, as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.
 
In our opinion, the financial statements referred to above present fairly, in
all material respects, the financial position of Milton Marketing Group Limited
and Subsidiaries as of November 30, 1995 and 1996, and the results of their
operations and their cash flows for each of the three years in the period ended
November 30, 1996 in conformity with generally accepted accounting principles.
 
Melville, New York
January 27, 1997
     (except with respect to the matters
     discussed in Note 11 as to which
     the date is               , 1997)
 
                                      F-22


<PAGE>

                         MILTON MARKETING GROUP LIMITED

                          CONSOLIDATED BALANCE SHEETS
                       (IN THOUSANDS, EXCEPT SHARE DATA)
 
<TABLE>
<CAPTION>
                                                                                      NOVEMBER 30,
                                                                                    ----------------     JUNE 30,
                                                                                     1995      1996        1997
                                                                                    ------    ------    -----------
                                                                                                        (UNAUDITED)
<S>                                                                                 <C>       <C>       <C>
                                     ASSETS
Current assets:
  Cash and cash equivalents......................................................   $  511    $   --      $    19
  Accounts receivable............................................................    1,058     3,266        3,510
  Unbilled production charges, at cost...........................................       49        87          273
  Other current assets...........................................................      147       415          581
                                                                                    ------    ------      -------
     Total current assets........................................................    1,765     3,768        4,383
Furniture, equipment and leasehold improvements, net.............................      634       870          948
Goodwill, net of accumulated amortization of $2, $44 and $79, respectively.......      994     1,800        1,707
Other assets.....................................................................        8        49          262
                                                                                    ------    ------      -------
                                                                                    $3,401    $6,487      $ 7,300
                                                                                    ------    ------      -------
                                                                                    ------    ------      -------
 
                      LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:
  Bank loans and overdrafts......................................................   $   24    $  406      $ 1,211
  Current portion of long-term debt..............................................      107       118          595
  Current portion of capitalized lease obligation................................       74       125           69
  Accounts payable...............................................................      340     1,144        1,538
  Accrued expenses...............................................................      936     1,977        1,418
  Advance billings...............................................................      441       534          684
                                                                                    ------    ------      -------
     Total current liabilities...................................................    1,922     4,304        5,515
Commitments (Note 9)
Long-term debt...................................................................      882       825          291
Capitalized lease obligation.....................................................       78       128          193
Minority interests...............................................................       89       143          268
Other liabilities................................................................       --        83           57
                                                                                    ------    ------      -------
                                                                                     2,971     5,483        6,324
                                                                                    ------    ------      -------
Stockholders' equity:
  Common stock, $1.68 par value, 10,000 shares authorized, and 2 shares issued
     and outstanding.............................................................       --        --           --
  Additional paid-in capital.....................................................       13        13           13
  Retained earnings..............................................................      423       925          914

  Cumulative foreign currency translation adjustments............................       (6)       66           49
                                                                                    ------    ------      -------
     Total stockholders' equity..................................................      430     1,004          976
                                                                                    ------    ------      -------
                                                                                    $3,401    $6,487      $ 7,300
                                                                                    ------    ------      -------
                                                                                    ------    ------      -------
</TABLE>
 
The accompanying notes to consolidated financial statements are an integral part
                            of these balance sheets.

                                      F-23


<PAGE>

                         MILTON MARKETING GROUP LIMITED

                       CONSOLIDATED STATEMENTS OF INCOME
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                                                                  SEVEN MONTHS
                                                                   YEAR ENDED NOVEMBER 30,       ENDED JUNE 30,
                                                                   ------------------------     ----------------
                                                                    1994     1995     1996       1996      1997
                                                                   ------   ------   ------     ------    ------
                                                                                                  (UNAUDITED)
<S>                                                                <C>      <C>      <C>        <C>       <C>
Revenues.........................................................  $2,666   $4,399   $9,895     $5,434    $8,147
                                                                   ------   ------   ------     ------    ------
Operating expenses:
  Salaries and related costs.....................................   1,474    2,531    6,793      3,860     6,333
  Other operating expenses.......................................     802    1,310    2,017        999     1,506
                                                                   ------   ------   ------     ------    ------
                                                                    2,276    3,841    8,810      4,859     7,839
Income from operations...........................................     390      558    1,085        575       308
Interest expense, net............................................      12       15       93         40        62
                                                                   ------   ------   ------     ------    ------
Income before provision for income taxes and minority
  interests......................................................     378      543      992        535       246
Provision for income taxes.......................................     117      159      366        197        91
Minority interests in net earnings of subsidiaries...............      39       68      124         81       126
                                                                   ------   ------   ------     ------    ------
Net income.......................................................  $  222   $  316   $  502     $  257    $   29
                                                                   ------   ------   ------     ------    ------
                                                                   ------   ------   ------     ------    ------
</TABLE>
 
The accompanying notes to consolidated financial statements are an integral part
                              of these statements.


                                      F-24

<PAGE>

                         MILTON MARKETING GROUP LIMITED

                CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY
                                 (IN THOUSANDS)
 
<TABLE>
<CAPTION>
                                                                                                CUMULATIVE
                                                                   ADDITIONAL                FOREIGN CURRENCY
                                                         COMMON     PAID-IN      RETAINED      TRANSLATION
                                                         STOCK      CAPITAL      EARNINGS      ADJUSTMENTS       TOTAL
                                                         ------    ----------    --------    ----------------    -----
<S>                                                      <C>       <C>           <C>         <C>                 <C>
Balance, November 30, 1993............................     $--        $ 13         $101            $ (1)         $ 113
  Net income..........................................     --           --          222              --            222
  Dividends...........................................     --           --         (130)             --           (130)
  Foreign currency translation adjustments............     --           --           --               8              8
                                                           ---        ----         ----            ----          -----
Balance, November 30, 1994............................     --           13          193               7            213
  Net income..........................................     --           --          316              --            316
  Dividends...........................................     --           --          (86)             --            (86)
  Foreign currency translation adjustments............     --           --           --             (13)           (13)
                                                           ---        ----         ----            ----          -----
Balance, November 30, 1995............................     --           13          423              (6)           430
  Net income..........................................     --           --          502              --            502
  Foreign currency translation adjustments............     --           --           --              72             72
                                                           ---        ----         ----            ----          -----
Balance, November 30, 1996............................     --           13          925              66          1,004
  Net income (unaudited)..............................     --           --           29              --             29
  Dividends (unaudited)...............................     --           --          (40)             --            (40)
  Foreign currency translation adjustments
     (unaudited)......................................     --           --           --             (17)           (17)
                                                           ---        ----         ----            ----          -----
Balance, June 30, 1997 (unaudited)....................     $--        $ 13         $914            $ 49          $ 976
                                                           ---        ----         ----            ----          -----
                                                           ---        ----         ----            ----          -----
</TABLE>
 
The accompanying notes to consolidated financial statements are an integral part
                              of these statements.

                                      F-25

<PAGE>

                         MILTON MARKETING GROUP LIMITED

                     CONSOLIDATED STATEMENTS OF CASH FLOWS
                                 (IN THOUSANDS)
 

<TABLE>
<CAPTION>
                                                                              YEAR ENDED             SEVEN MONTHS
                                                                              NOVEMBER 30,           ENDED JUNE 30,
                                                                         -----------------------     ---------------
                                                                         1994    1995     1996        1996     1997
                                                                         -----   -----   -------     -------   -----
                                                                                                       (UNAUDITED)
<S>                                                                      <C>     <C>     <C>         <C>       <C>
Cash flows from operating activities:
  Net income...........................................................  $ 222   $ 316   $   502     $   257   $  29
    Adjustments to reconcile net income to net cash
    provided by operating activities:
      Depreciation and amortization....................................    114     136       225         100     121
      Minority interest in net earnings................................     39      68       124          81     126
      (Gain)/loss on sale of fixed assets..............................    (24)      1        18          --      --
    Changes in operating assets and liabilities, net of effect of
    acquisitions:
      Accounts receivable..............................................    418    (138)   (1,456)     (2,197)   (244)
      Unbilled production charges......................................    538      28       (21)       (193)   (186)
      Other current assets.............................................     --     (22)     (166)         (9)   (166)
      Other assets.....................................................     --      --        --          --    (213)
      Accounts payable.................................................   (536)   (614)     (359)        640     394
      Accrued expenses.................................................      7     763       876         833    (487)
      Advance billings.................................................   (502)     74        50         380     150
      Other liabilities................................................     --      --        18          60     (26)
                                                                         -----   -----   -------     -------   -----
Net cash provided by (used in) operating activities....................    276     612      (189)        (48)   (502)
                                                                         -----   -----   -------     -------   -----
Cash flows from investing activities:
  Net purchase price of acquisitions (Note 3)..........................     --    (639)     (242)       (215)     --
  Capital expenditures, net............................................    (95)   (203)     (214)        (66)    (72)
  Proceeds from the sale of fixed assets...............................     58      63        50          --      --
                                                                         -----   -----   -------     -------   -----
Net cash (used in) investing activities................................    (37)   (779)     (406)       (281)    (72)
                                                                         -----   -----   -------     -------   -----
Cash flows from financing activities:
  Payment of majority stockholder dividends............................   (130)    (86)       --          --      --
  Payment of minority interest shareholders dividends..................    (23)    (15)       --          --     (55)
  Proceeds from bank overdraft.........................................     --      --       309         (23)    805
  Repayment of bank loans..............................................     --      --      (131)        (27)    (57)
  Proceeds from bank loans.............................................     --     613        --          --      --
  Capital lease repayments.............................................    (88)   (152)      (77)        (21)    (83)
                                                                         -----   -----   -------     -------   -----
Net cash (used in) provided by financing activities....................   (241)    360       101         (71)    610
                                                                         -----   -----   -------     -------   -----
Effect of exchange rate changes on cash................................     12     (14)      (17)         22     (17)
                                                                         -----   -----   -------     -------   -----
Net increase/(decrease) in cash and cash equivalents...................     10     179      (511)       (378)     19
Cash and cash equivalents at beginning of year.........................    322     332       511         511      --
                                                                         -----   -----   -------     -------   -----
Cash and cash equivalents at end of year...............................  $ 332   $ 511   $    --     $   133   $  19
                                                                         -----   -----   -------     -------   -----
                                                                         -----   -----   -------     -------   -----

Supplemental disclosure of cash flow information:
  Cash paid for taxes..................................................  $ 113   $ 151   $    67     $    --   $ 262
                                                                         -----   -----   -------     -------   -----
                                                                         -----   -----   -------     -------   -----
  Cash paid for interest...............................................  $  21   $  22   $    88     $    40   $  62
                                                                         -----   -----   -------     -------   -----
                                                                         -----   -----   -------     -------   -----
</TABLE>
 
The accompanying notes to consolidated financial statements are an integral part
                              of these statements.

                                      F-26


<PAGE>

                         MILTON MARKETING GROUP LIMITED

                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
1. ORGANIZATION AND BUSINESS
 
     In 1997, the company formerly known as Siteinput Limited changed its name
to Milton Marketing Group Limited. Milton Marketing Group Limited ('Milton'), a
United Kingdom corporation, was formed in October 1995. Through its predecessor,
Milton Marketing Limited, Milton, together with its subsidiaries (Milton and its
subsidiaries are collectively referred to as the 'Company'), provides a broad
range of integrated marketing services including strategic planning, product
positioning, database marketing, field marketing, new product development,
advertising, public relations, marketing research, and sales promotion. Milton
is comprised of its wholly-owned subsidiary Effective Sales Personnel Limited
('ESP') and its majority-owned subsidiaries, Milton Marketing Limited ('MML'),
Headcount Limited ('HL'), PDM Communications Limited ('PDM') and Milton Cater
Limited ('MCL').
 
2. SIGNIFICANT ACCOUNTING POLICIES
 
  Principles of Consolidation
 
     The accompanying consolidated financial statements include the accounts of
the Company and its wholly-owned and majority-owned subsidiaries. All
intercompany accounts and transactions have been eliminated.
 
  Foreign Currency Translation
 
     All assets and liabilities of the Company are translated into United States
dollars from United Kingdom Pound Sterling at period-end exchange rates. Income
and expense items are translated at average exchange rates prevailing during
each fiscal period. The resulting translation adjustments are recorded as a
separate component of stockholders' equity.
 
  Revenue Recognition
 
     Substantially all revenues are derived from fees from clients for creative
concept development, production of advertising and marketing materials,
consulting on the market positioning of pharmaceutical products, the supply of
long and short-term personnel for client promotional purposes and the provision
of public relations services to public health service institutions.
 
     Substantially all revenues from creative fees are recognized when earned
either under monthly retainer agreements or on an actual time incurred basis.
Fees for production are earned when the production materials are completed.
Advanced production billings represent project costs and fees that are billed to
clients as projects progress and are recognized at completion. Income for field
marketing support is recognized as services are provided.
 
     Accounts receivable include fees recognized, project costs, and media and

production costs incurred on behalf of clients, which are paid for by the
Company and billed to clients. The Company records gross contract revenues for
contract sales services and the related direct costs are included in salaries
and related costs on the accompanying consolidated statements of income.
 
  Concentration of Credit Risk
 
     The Company provides services to a range of clients operating mostly in the
healthcare, food and beverage and communication industries. For the year ended
November 30, 1996, the Company had one client which constituted approximately
13% of total revenues. In addition, the Company's five largest clients
represented 45% of total revenues for that period. The Company had one client
which constituted approximately 16% and 25% of total 1995 and 1994 revenues,
respectively. The Company extends credit to all qualified clients, but does not
believe that it is exposed to any undue concentration of credit risk to any
significant degree. The Company maintains reserves for potential credit losses,
but has not experienced any material losses to individual clients or groups of
clients.
 
                                      F-27

<PAGE>

                         MILTON MARKETING GROUP LIMITED

            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
2. SIGNIFICANT ACCOUNTING POLICIES--(CONTINUED)

  Cash and Cash Equivalents
 
     For purposes of the consolidated balance sheets and consolidated statements
of cash flows, the Company considers all highly liquid debt instruments
purchased with original maturities of three months or less to be cash
equivalents, including commercial paper and money market mutual funds.
 
  Unbilled Production Charges
 
     Unbilled production charges consists principally of costs incurred in
producing marketing communications for clients and field marketing personnel to
be billed. Such amounts will be billed to clients at either a defined stage of
the project or when production is complete.
 
  Furniture, Equipment and Leasehold Improvements
 
     Furniture, equipment and leasehold improvements are stated at cost, net of
accumulated depreciation and amortization. Depreciation and amortization are
computed using both accelerated and straight-line methods over the following
periods:
 
<TABLE>
<S>                                          <C>

Furniture.................................   4-10 years
Equipment.................................   4-14 years
Motor Vehicles............................   4-8 Years
Leasehold Improvements....................   Lesser of lease term or useful life
</TABLE>
 
  Equipment Held under Capital Leases
 
     Assets held under capital leases is accounted for in accordance with
Statement of Financial Accounting Standards No. 13, 'Accounting for Leases,' and
recorded in Property, Plant and Equipment. The present value of the related
liability is included in capitalized lease obligations.
 
  Goodwill
 
     Goodwill represents the Company's excess cost over net assets acquired and
is being amortized on a straight-line basis over the estimated useful life of
the assets. Amounts recognized to date have been amortized over 30 years from
the original date of acquisition. Amortization expense of goodwill for the years
ended November 30, 1994, 1995 and 1996 amounted to $0, $2 and $42, respectively,
and for the seven months ended June 30, 1996 and 1997 amounted to $23 and $35,
respectively (unaudited).
 
     During 1996, the Company adopted Statement of Financial Accounting
Standards No. 121 (SFAS No. 121), 'Accounting for the Impairment of Long-Lived
Assets and Long-Lived Assets to be Disposed of.' This statement requires the
Company to review long-lived assets, including certain intangibles and goodwill,
for impairment whenever events or changes in circumstances indicate that the
carrying amount of an asset may not be recoverable. The effect of adoption was
not material.
 
  Income Taxes
 
     The Company accounts for income taxes in accordance with Statement of
Financial Accounting Standards No. 109, 'Accounting for Income Taxes.' This
statement requires a liability approach for measuring deferred taxes based on
temporary differences between the financial statement and income tax bases of
assets and liabilities existing at each balance sheet date using enacted rates
for the years in which the taxes are expected to be paid or recovered. The
Company has not recorded any deferred tax assets or liabilities as any
differences between book and income tax recognition are immaterial.
 
                                      F-28

<PAGE>

                         MILTON MARKETING GROUP LIMITED

            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
2. SIGNIFICANT ACCOUNTING POLICIES--(CONTINUED)


  Use of Estimates
 
     The preparation of financial statements in conformity with generally
accepted accounting principles requires management to make estimates and
assumptions that affects the amounts reported in the financial statements and
accompanying notes. Actual results could differ from those estimates.
 
  Recently Issued Accounting Standards
 
     In March 1997, the Financial Accounting Standards Board issued Statement of
Financial Accounting Standards ('SFAS') No. 128, Earnings Per Share. This
statement establishes standards for computing and presenting earnings per share
('EPS'), replacing the presentation of currently required primary EPS with a
presentation of Basic EPS. For entities with complex capital structures, the
statement requires the dual presentation of both Basic EPS and Diluted DPS on
the face of the statement of income. Under this new standard, Basic EPS is
computed based on weighted average shares outstanding and excludes any potential
dilution; Diluted EPS reflects potential dilution from the exercise or
conversion of securities into common stock or from other contracts to issue
common stock and is similar to the currently required fully diluted EPS. SFAS
128 is effective for financial statements issued for periods ending after
December 15, 1997, including interim periods, and earlier application is not
permitted.
 
3. ACQUISITIONS OF BUSINESSES
 
  Effective Sales Personnel Limited
 
     In November 1995, the Company acquired all of the outstanding stock of ESP
for a purchase price of $1,130. The purchase price was funded by cash and a $462
note due March 1998.
 
  Milton Cater Limited
 
     MCL was formed in April 1996, and the Company acquired 51% of its equity in
May 1996. The remaining 49% of MCL's equity is owned by a key employee and must
be purchased by the Company on the earliest of May 23, 2001, the sale or
disposal of MCL or the Company, or the Company being the subject of an initial
public offering. The purchase price is set at 60% of defined average annual
Gross Profits of MCL, as defined in the agreement, in excess of $588 for the
three years prior to purchase, subject to a maximum purchase price of $504. At
November 30, 1996 the purchase price would be immaterial.
 
  Milton Marketing Limited
 
     In April 1996, the Company acquired an additional 7.5% interest in MML for
$234, which increased the Company's interest in MML to 92.5%.
 
  PDM Communications Limited
 
     In November 1996, the Company acquired a 75% interest in PDM for a cash
purchase price of $32.
 
     The minority stockholder has a put option and the Company has a call option

with respect to the remaining 25% of PDM shares not owned by the Company. The
stockholder put option would require payment of 18.5% of Gross Income of PDM, as
defined in the agreement, for the period from November 26, 1996 to date of
exercise. The Company's call option would require payment on 25% of Gross Income
to date of exercise. The stockholder put option is exercisable at any time up to
November 30, 1998, provided that PDM has generated positive Gross Income, after
personnel costs during the period. The Company's call option is exercisable if a
certain key employee leaves PDM, or if PDM or the Company is sold or the subject
of an initial public offering.
 
                                      F-29

<PAGE>

                         MILTON MARKETING GROUP LIMITED

            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
3. ACQUISITIONS OF BUSINESSES--(CONTINUED)

     As a result of the three acquisitions discussed above, goodwill was
recorded as follows:
 
<TABLE>
<CAPTION>
                                                                                ESP      MML       PDM
                                                                               ------    ----    -------
<S>                                                                            <C>       <C>     <C>
Assets......................................................................   $  346    $ --    $   717
Minority share of net assets acquired.......................................       --      46         --
Goodwill....................................................................    1,027     188        523
Liabilities.................................................................     (243)     --     (1,208)
                                                                               ------    ----    -------
  Total purchase price......................................................   $1,130    $234    $    32
                                                                               ------    ----    -------
                                                                               ------    ----    -------
</TABLE>
 
  Pro Forma Results of Operations
 
     Summarized below are the unaudited pro forma results of operations of the
Company as though the ESP acquisition had occurred at the beginning of 1994 and
the MML and PDM acquisitions had occurred at the beginning of 1995. Adjustments
have been made for pro forma income taxes and amortization of goodwill related
to these transactions.
 
<TABLE>
<CAPTION>
                                                                               YEAR ENDED NOVEMBER 30,
                                                                             ---------------------------
Pro Forma:                                                                    1994      1995      1996
                                                                             ------    ------    -------

<S>                                                                          <C>       <C>       <C>
  Revenues................................................................   $5,609    $6,634    $10,282
  Net income..............................................................      357       392        135
</TABLE>
 
     These pro forma results of operations are not necessarily indicative of the
actual results of operations that would have occurred had the acquisitions been
made at the beginning of 1994 or 1995 or of results which may occur in the
future.
 
4. FURNITURE, EQUIPMENT AND LEASEHOLD IMPROVEMENTS
 
     Motor vehicles, furniture, equipment and leasehold improvements consist of
the following:
 
<TABLE>
<CAPTION>
                                                                                                 
                                                                                                   
                                                                NOVEMBER 30,    NOVEMBER 30,       JUNE 30,
                                                                    1995            1996            1997
                                                                ------------    ------------    -------------
                                                                                                 (UNAUDITED)
<S>                                                             <C>             <C>              <C>
Motor vehicles...............................................      $  204          $  265         $   265
Furniture and equipment......................................         670             996           1,070
  Leasehold improvements.....................................         126             163             163
Equipment held under capital leases..........................         284             395             485
                                                                   ------          ------         -------
                                                                    1,284           1,819           1,983
Less: Accumulated depreciation and amortization..............         650             949           1,035
                                                                   ------          ------         -------
                                                                   $  634          $  870         $   948
                                                                   ------          ------         -------
                                                                   ------          ------         -------
</TABLE>
 
     Depreciation and amortization expense of furniture, equipment and leasehold
improvements for the years ended November 30, 1994, 1995 and 1996 amounted to
approximately $114, $134 and $183, respectively, and for the seven months ended
June 30, 1996 and 1997 amounted to $84 and $106, respectively (unaudited).
 
                                      F-30

<PAGE>

                         MILTON MARKETING GROUP LIMITED

            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
5. ACCRUED EXPENSES
 

     Major components of accrued expenses included:
 
<TABLE>
<CAPTION>
                                                                                                 
                                                                                                   
                                                                NOVEMBER 30,    NOVEMBER 30,     JUNE 30,
                                                                    1995            1996           1997
                                                                ------------    ------------    ----------
                                                                                                (UNAUDITED)
<S>                                                             <C>             <C>             <C>
Value added and payroll taxes................................      $  445          $1,155         $   836
Payroll......................................................          --             356             387
Directors fees...............................................         130              --              --
Other........................................................         361             466             195
                                                                   ------          ------         -------
                                                                   $  936          $1,977         $ 1,418
                                                                   ------          ------         -------
                                                                   ------          ------         -------
</TABLE>
 
6. BANK LOANS AND OVERDRAFT
 
     The Company has the following loans outstanding:
 
<TABLE>
<CAPTION>
                                                                NOVEMBER 30,    NOVEMBER 30,     JUNE 30,
                                                                    1995            1996           1997
                                                                ------------    ------------    ----------
                                                                                                (UNAUDITED)
<S>                                                             <C>             <C>             <C>
Term loan(a).................................................      $  535          $  470         $   407
Business development loan(b).................................          57              38              23
Overdraft facility(c)........................................          --             379           1,211
4% loan notes(d).............................................         421             462             456
                                                                   ------          ------         -------
                                                                    1,013           1,349           2,097
Less: Current portion........................................         131             524           1,806
                                                                   ------          ------         -------
                                                                   $  882          $  825         $   291
                                                                   ------          ------         -------
                                                                   ------          ------         -------
</TABLE>
 
------------------
a) During November 1995, a bank provided a term loan of $588 to the Company
   which bears interest at the UK base rate (6% as of November 30, 1996) plus 2%
   per annum and is payable in installments of $58 every May and November with
   the final installment due in November 2000. The term loan requires the
   Company to maintain certain financial covenants. As of November 30, 1996, the
   Company was in compliance with all of the provisions of the term loan.
 
b) This loan bears interest at 10.5% per annum and matures in April 1998.

 
c) The Company has in place a $672 overdraft facility with a bank which bears
   interest at the UK base rate plus 2% per annum. As of November 30, 1996, the
   outstanding balance was approximately $379. At June 30, 1997, the bank has
   allowed the Company to exceed the overdraft facility limit. The Company is
   currently negotiating with the bank to increase the limit of the facility
   (unaudited).
 
d) In connection with the ESP acquisition the Company has issued a $462, 4%
   unsecured note, which is payable in March 1998.
 
     At November 30, 1996, maturities of debt are as follows:
 
<TABLE>
<S>                                                               <C>
1997...........................................................   $524
1998...........................................................    593
1999...........................................................    116
2000...........................................................    116
</TABLE>
 
7. CAPITALIZED LEASE OBLIGATION
 
     The Company enters into leases for computer equipment and motor vehicles.
The lease payments are payable monthly on a straight-line basis. The assets
relating to the leases are capitalized and amortized over a period approximating
the lease period.
 
                                      F-31

<PAGE>

                         MILTON MARKETING GROUP LIMITED

            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
7. CAPITALIZED LEASE OBLIGATION--(CONTINUED)

     Minimum future lease payments under capital leases as of November 30 are as
follows:
 
<TABLE>
<S>                                                                     <C>
1997.................................................................   $141
1998.................................................................    101
1999.................................................................     44
                                                                        ----
Total minimum lease payments.........................................    286
Less: Amount representing interest...................................     33
                                                                        ----
Present value of minimum lease payments..............................   $253
                                                                        ----

                                                                        ----
</TABLE>
 
     Interest rates on capitalized leases vary from 11% to 15% and are imputed
based on the lessor's implicit rate of return.
 
8. INCOME TAXES
 
     The following table reconciles the U.K. Federal statutory rate to the
Company's effective income tax rate for the years ended November 30, 1994, 1995
and 1996:
 
<TABLE>
<CAPTION>
                                                                                          NOVEMBER 30,
                                                                                      --------------------
                                                                                      1994    1995    1996
                                                                                      ----    ----    ----
<S>                                                                                   <C>     <C>     <C>
Statutory rate.....................................................................    33%     33%     33%
Nondeductible expenses.............................................................    ---     ---      4%
Small and marginal company rate relief.............................................    (2%)    (4%)    ---
                                                                                       ---     ---     ---
Effective rate.....................................................................    31%     29%     37%
                                                                                       ---     ---     ---
                                                                                       ---     ---     ---
</TABLE>
 
     The Company has not recorded any deferred tax assets or liabilities as any
differences between book and income tax recognition are immaterial.
 
9. COMMITMENTS
 
     The Company has entered into various leases for property. All leases are
payable in quarterly installments, and are accounted for on a straight line
basis over the term of the lease.
 
     The following is a schedule of the minimum annual lease payments due:
 
<TABLE>
<S>                                                                           <C>
1997.......................................................................   $  393
1998.......................................................................      393
1999.......................................................................      393
2000.......................................................................      393
2001.......................................................................      393
Thereafter.................................................................    2,048
</TABLE>
 
     Total rent expense incurred for the years ended November 30, 1994, 1995 and
1996 was approximately $116, $107 and $229, respectively, and for the seven
months ended June 30, 1996 and 1997 was approximately $118 and $225,
respectively (unaudited).
 

  Employment Agreements
 
     The Company has entered into employment agreements (the 'Agreements') with
certain key employees. The Agreements contain provisions for base salary and
incentives based upon certain performance measures, and are subject to
termination by either party. The aggregate annual minimum base compensation
required by the Agreements is approximately $200.
 
                                      F-32

<PAGE>

                         MILTON MARKETING GROUP LIMITED

            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
9. COMMITMENTS--(CONTINUED)

  Employee Benefits
 
     The Company makes non-contractual payments into the personal pension plans
of various directors and senior management. For the years ended November 30,
1994, 1995, and 1996, the Company has contributed $56, $74, and $41,
respectively, and for the seven months ended June 30, 1996 and 1997, the Company
has contributed $34 and $37, respectively (unaudited).
 
10. INTERIM FINANCIAL STATEMENTS
 
     The consolidated financial statements of Milton Marketing Group Limited as
of and for the seven months ended June 30, 1996 and 1997, presented herein have
been prepared by the Company without audit, pursuant to the rules and
regulations of the Securities and Exchange Commission. The financial statements
reflect all adjustments (consisting of only normal recurring adjustments) which,
in the opinion of management, are necessary to present fairly the combined
financial position, results of operations and cash flows of the Company as of
June 30, 1996 and 1997, and for the periods then ended. The Company's interim
results may fluctuate as a result of a number of factors and are not necessarily
indicative of the results to be obtained for the full year.
 
11. SUBSEQUENT EVENTS
 
     Pursuant to a Letter of Intent between the Company and Girgenti, Hughes,
Butler & McDowell, Inc. and its affiliated entities ('GHB&M'), the Company and
GHB&M have agreed to cause their respective stockholders to enter into
definitive agreements with Healthworld Corporation ('Healthworld') pursuant to
which all outstanding shares of common stock of each of the companies comprising
the Company and GHB&M will be exchanged for shares of Healthworld common stock
as of the effective date of the Offering (as defined below) (the
'Consolidation'). Concurrent with the Consolidation, the four stockholders
holding all of the minority interests in the entities comprising the Company
will contribute their interests in such respective companies to Healthworld in
exchange for shares of common stock of Healthworld.

 
     Healthworld is pursuing an initial public offering of its securities (the
'Offering'). The Offering contemplates the sale of 2,100 shares of Healthworld's
common stock at an offering price between $8.00 and $9.50 per share before
underwriting commissions and Offering expenses. Healthworld plans to use the
proceeds of the Offering for working capital and general corporate purposes.
 
                                      F-33

<PAGE>
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 
     NO UNDERWRITER, DEALER, SALESMAN OR OTHER PERSON HAS BEEN AUTHORIZED TO
GIVE ANY INFORMATION OR TO MAKE ANY REPRESENTATIONS IN CONNECTION WITH THIS
OFFERING, OTHER THAN THOSE CONTAINED IN THIS PROSPECTUS, AND, IF GIVEN OR MADE,
SUCH INFORMATION OR REPRESENTATIONS MUST NOT BE RELIED UPON AS HAVING BEEN
AUTHORIZED BY THE COMPANY OR THE UNDERWRITERS. THIS PROSPECTUS DOES NOT
CONSTITUTE AN OFFER TO SELL, OR A SOLICITATION OF AN OFFER TO BUY, ANY
SECURITIES OFFERED HEREBY BY ANYONE IN ANY JURISDICTION IN WHICH SUCH OFFER OR
SOLICITATION IS NOT AUTHORIZED OR IN WHICH THE PERSON MAKING SUCH OFFER OR
SOLICITATION IS NOT AUTHORIZED OR IN WHICH THE PERSON MAKING SUCH OFFER OR
SOLICITATION IS NOT QUALIFIED TO DO SO OR TO ANYONE TO WHOM IT IS UNLAWFUL TO
MAKE SUCH OFFER OR SOLICITATION. NEITHER THE DELIVERY OF THIS PROSPECTUS NOR ANY
SALE MADE HEREUNDER SHALL, UNDER ANY CIRCUMSTANCES, CREATE ANY IMPLICATION THAT
THE INFORMATION CONTAINED HEREIN IS CORRECT AS OF ANY TIME SUBSEQUENT TO THE
DATE OF THIS PROSPECTUS.
 
                            ------------------------
 
                               TABLE OF CONTENTS
 
<TABLE>
<CAPTION>
                                                     PAGE
                                                     ----
<S>                                                  <C>
Prospectus Summary................................     3
Risk Factors......................................     6
The Consolidation.................................    11
Use of Proceeds...................................    12
Dividend Policy...................................    12
Dilution..........................................    13
Capitalization....................................    14
Selected Pro Forma Combined Financial
  Information.....................................    15
Selected Financial Information of GHB&M
  and Milton......................................    16
Management's Discussion and Analysis of Financial
  Condition and Results of Operations.............    17
Business..........................................    24
Management........................................    33

Certain Relationships and Related
  Transactions....................................    38
Principal Stockholders............................    39
Description of Capital Stock......................    40
Shares Eligible for Future Sale...................    42
Underwriting......................................    43
Legal Matters.....................................    44
Experts...........................................    44
Forward Looking Statement.........................    44
Additional Information............................    45
Index to Financial Statements.....................   F-1
</TABLE>
 
                            ------------------------
 
     UNTIL              , 1997 (25 DAYS AFTER THE DATE OF THIS PROSPECTUS), ALL
DEALERS EFFECTING TRANSACTIONS IN THE COMMON STOCK, WHETHER OR NOT PARTICIPATING
IN THIS DISTRIBUTION, MAY BE REQUIRED TO DELIVER A PROSPECTUS. THIS REQUIREMENT
IS IN ADDITION TO THE OBLIGATION OF DEALERS TO DELIVER A PROSPECTUS WHEN ACTING
AS UNDERWRITERS AND WITH RESPECT TO THEIR UNSOLD ALLOTMENTS OR SUBSCRIPTIONS.
 
                                2,100,000 SHARES
                                     [LOGO]
                                  HEALTHWORLD
                                  CORPORATION
                                  COMMON STOCK
                            ------------------------
                                   PROSPECTUS
                            ------------------------
                                UNTERBERG HARRIS
                             PENNSYLVANIA MERCHANT
                                   GROUP LTD
 
                                           , 1997
 
                       ---------------------------------------------------------
                       ---------------------------------------------------------
                       ---------------------------------------------------------
                       ---------------------------------------------------------
<PAGE>
                                    PART II
                     INFORMATION NOT REQUIRED IN PROSPECTUS
 
ITEM 13. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION
 
     Set forth below is an estimate of the approximate amount of fees and
expenses (other than underwriting commissions and discounts) payable by the
Registrant in connection with the issuance and distribution of the Common Stock
pursuant to the Prospectus contained in this Registration Statement.
 
<TABLE>
<CAPTION>
                                                               APPROXIMATE
                                                                 AMOUNT

                                                               -----------
<S>                                                            <C>
Securities and Exchange Commission registration fee.........    $6,952.27
NASD filing fee.............................................     2,794.25
Nasdaq National Market listing fee..........................       *
Accountants' fees and expenses..............................       *
Blue Sky fees and expenses..................................       --
Legal fees and expenses.....................................       *
Transfer Agent and Registrar fees and expenses..............       *
Printing and engraving expenses.............................       *
Miscellaneous...............................................       *
                                                               -----------
     Total..................................................    $  *
                                                               -----------
                                                               -----------
</TABLE>
 
------------------
* To be completed by amendment.
 
ITEM 14. INDEMNIFICATION OF DIRECTORS AND OFFICERS
 
     The Registrant's Certificate of Incorporation and By-laws provide that the
Registrant shall indemnify its directors to the full extent permitted by the
General Corporation Law of the State of Delaware (the 'DGCL') and may indemnify
its officers and employees to such extent, except that the Registrant shall not
be obligated to indemnify any such person (i) with respect to proceedings,
claims or actions initiated or brought voluntarily by any such person and not by
way of defense, or (ii) for any amounts paid in settlement of an action
indemnified against by the Registrant without the prior written consent of the
Registrant without the prior written consent of the Registrant. The Registrant
intends to enter into indemnity agreements with each of its directors. These
agreements may require the Registrant, among other things, to indemnify such
directors against certain liabilities that may arise by reason of their status
or service as directors, and to advance expenses to them as they are incurred,
provided that they undertake to repay the amount advanced if it is ultimately
determined by a court that they are not entitled to indemnification, and to
obtain directors' liability insurance if available on reasonable terms.
 
     In addition, the Registrant's Certificate of Incorporation provides that a
director of the Registrant shall not be personally liable to the Registrant or
its stockholders for monetary damages for breach of his or her fiduciary duty as
director, except for liability (i) for any breach of the director's duty of
loyalty to the Registrant or its stockholders, (ii) for acts or omissions not in
good faith or which involve intentional misconduct or a knowing violation of
law, (iii) for willful or negligent conduct in paying dividends or repurchasing
stock out of other than lawfully available funds or (iv) for any transaction
from which the director derives an improper personal benefit.
 
     Reference is made to Section 145 of the DGCL which provides for
indemnification of directors and officers in certain circumstances.
 
ITEM 15. RECENT SALES OF UNREGISTERED SECURITIES
 

     In connection with the Consolidation, the Registrant will, as of the date
of this Registration Statement, issue an aggregate of 5,000,000 shares of Common
Stock to the stockholders of GHB&M and Milton in exchange for all of their stock
of GHB&M and Milton. Such transaction will be effected in reliance upon the
exemption from the registration of the Securities Act contained in Section 4(2)
of the Securities Act and the rules and regulations promulgated thereunder on
the basis that such transaction did not involve any public offering. No
underwriters
 
                                      II-1
<PAGE>
were engaged with respect to such transaction and no underwriting discounts or
commissions will be paid in connection with the sale of such securities.
 
ITEM 16. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES
 
     (a) Exhibits
 
     The following documents are filed as part of this Registration Statement:
 
<TABLE>
<CAPTION>
 EXHIBIT
  NUMBER     DESCRIPTION
----------   --------------------------------------------------------------------------------------------------------
<S>          <C>
    1.01      --   Form of Underwriting Agreement between the Registrant and Unterberg Harris and Pennsylvania
                   Merchant Group Ltd, as representatives of several underwriters.
    2.01      --   Letter of Intent between Girgenti, Hughes, Butler & McDowell, Inc. ('GH') and its affiliated
                   entities and Milton Marketing Group Limited and its subsidiaries, dated November 14, 1996, as
                   amended July 24, 1997.
    2.02      --   Form of Agreement and Plan of Organization by and among the Registrant, Steven Girgenti, Francis
                   Hughes, William Butler and Herbert Ehrenthal.
    2.03      --   Form of Agreement and Plan of Organization between the Registrant and William Leslie Milton.
    2.04      --   Form of Agreement and Plan of Organization by and between the Registrant and minority
                   stockholders.
    3.01      --   Restated Certificate of Incorporation of the Registrant.
    3.02      --   Amended and Restated Bylaws of the Registrant.
    4.01*     --   Specimen Common Stock Certificate.
    5.01*     --   Opinion of Rosenman & Colin LLP.
   10.01      --   Term Loan Facility, dated November 6, 1995, by and between Siteinput Limited (n/k/a Milton
                   Marketing Group Limited) and The Bank of Scotland plc., as amended by letter dated July 23, 1997.
   10.02      --   Line of Credit between The Chase Manhattan Bank, N.A. ('Chase') and GH and each of its affiliated
                   entities, dated January 22, 1996.
   10.03      --   Line of Credit between Chase and GH and each of its affiliated entities, dated January 17, 1997.
   10.04      --   Promissory Note made by GH and its affiliated entities for the benefit of Chase, dated January 31,
                   1996.
   10.05*     --   Registrant's 1997 Incentive Stock Option Plan.
</TABLE>
 
<TABLE>
<C>          <C>   <S>
   10.06*     --   Employment Agreement by and between the Registrant and Steven Girgenti.
   10.07*     --   Employment Agreement by and between the Registrant and William Leslie Milton.

   10.08*     --   Employment Agreement by and between the Registrant and William Butler.
   10.09*     --   Employment Agreement by and between the Registrant and Herbert Ehrenthal.
   10.10*     --   Employment Agreement by and between the Registrant and Francis Hughes.
   10.11      --   Employment Agreement by and between the Registrant and Stuart Diamond.
   10.12      --   License Agreement between the Registrant and Healthworld, B.V.
   10.13      --   Lease for office space located at 100 Avenue of the Americas, New York, NY, between The Rector,
                   Church-Wardens and Vestrymen of Trinity Church in the City of New York and GH, dated July 15,
                   1994.
   10.14      --   Agreement for the sale and purchase of share capital of Effective Sales Personnel Limited between
                   Gloria Olive Sargent and Siteinput Limited, dated November 8, 1995.
</TABLE>
 
------------------
* To be filed by amendment.
 
                                      II-2
<PAGE>
<TABLE>
<CAPTION>
 EXHIBIT
  NUMBER     DESCRIPTION
----------   --------------------------------------------------------------------------------------------------------
   10.15      --   Supplemental Agreement relating to the sale and purchase of share capital of Effective Sales
                   Personnel Limited between Gloria Olive Sargent and Siteinput Limited, dated November 29, 1996.
<C>          <C>   <S>
   10.16      --   Agreement for the sale and purchase of shares in PDM Communications Limited among Leonard Moreton,
                   Lizabeth Jenny Moreton, Leonard Moreton & Co. and Siteinput Limited, dated November 26, 1996.
   10.17      --   Agreement for the sale and purchase of shares in PDM Communications Limited between William
                   Annandale and Siteinput Limited, dated November 21, 1996.
   10.18      --   Joint Venture Agreement between Siteinput Limited and Claire Denise Cater dated May 23, 1996.
   10.19      --   Share Sale Agreement between Wendy Carter and Siteinput Limited dated April 4, 1996.
   10.20      --   Overdraft Facility, dated November 6, 1995, between Siteinput Limited and The Bank of Scotland
                   plc.
   21.01      --   Subsidiaries of the Registrant.
   23.01      --   Consent of Arthur Andersen LLP.
   23.02*     --   Consent of Rosenman & Colin LLP (included in Exhibit 5.01).
   24.01      --   Power of attorney (included on page II-4).
   27.01      --   Financial Data Schedule.
   27.02      --   Financial Data Schedule.
   27.03      --   Financial Data Schedule.
   27.04      --   Financial Data Schedule.
   27.05      --   Financial Data Schedule.
   27.06      --   Financial Data Schedule.
   27.07      --   Financial Data Schedule.
   27.08      --   Financial Data Schedule.
   99.01      --   Consents of Nominee Directors.
</TABLE>
 
     (b) Financial Statement Schedule
 
        None.
 
ITEM 17. UNDERTAKINGS
 

     The Registrant hereby undertakes:
 
          (1) To provide to the Underwriters at the closing specified in the
     underwriting agreement, certificates in such denominations and registered
     in such names as required by the Underwriters to permit prompt delivery to
     each purchaser.
 
          (2) For purposes of determining any liability under the Securities
     Act, the information omitted from the form of prospectus filed as part of
     this Registration Statement in reliance upon Rule 430A and contained in a
     form of prospectus filed by the Registrant pursuant to Rule 424(b)(1) or
     (4) or 497(h) under the Securities Act shall be deemed to be part of this
     Registration Statement as of the time it was declared effective.
 
          (3) For the purpose of determining any liability under the Securities
     Act, each post-effective amendment that contains a form of prospectus shall
     be deemed to be a new registration statement relating to the securities
     offered therein, and the offering of such securities at that time shall be
     deemed to be the initial bona fide offering thereof.
 
     Insofar as indemnification for liabilities arising under the Securities Act
may be permitted to directors, officers and controlling persons of the
Registrant pursuant to the applicable provisions of the DGCL, or

                                      II-3

<PAGE>

otherwise, the Registrant has been advised that in the opinion of the
Commission, such indemnification is against public policy as expressed in the
Securities Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
Registrant of expenses incurred or paid by a director, officer or controlling
person of the Registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act and will be governed by the final adjudication of such issue.
 
                                      II-4
<PAGE>
                                   SIGNATURES
 
     Pursuant to the requirements of the Securities Act of 1933, the Registrant
has duly caused this Registration Statement to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of New York, State of New
York, on the 29th day of August 1997.
 
                                          HEALTHWORLD CORPORATION
 
                                          By: ________/s/ STEVEN GIRGENTI_______
                                                       Steven Girgenti
                                                 Chairman of the Board and
                                                  Chief Executive Officer
 
                               POWER OF ATTORNEY
 

     Know all men by these presents, that each person whose signature appears
below constitutes and appoints Steven Girgenti and William Leslie Milton and
each of them singly, his true and lawful attorney-in-fact and agent, with full
power of substitution and resubstitution, for him and in his name, place and
stead, in any and all capacities (including his capacity as a director and
officer of Healthworld Corporation) to sign any and all amendments (including
post-effective amendments) to this Registration Statement (and in addition, any
registration statement filed pursuant to 462(b) under the Securities Act of
1933, for the offering to which this Registration Statement relates) and to file
the same, with all exhibits thereto, and other documents in connection
therewith, with the Securities and Exchange Commission, granting unto each said
attorney-in-fact and agent, full power and authority to do and perform each and
every act and thing requisite and necessary to be done in and about the
premises, as fully to all intents and purposes as he might or could do in
person, hereby ratifying and confirming all that each said attorney-in-fact and
agent, or their or his substitute or substitutes, may lawfully do or cause to be
done by virtue hereof. This Power of Attorney may be signed in several
counterparts.
 
     Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below by the following persons in the
capacities and on the dates indicated.
 
<TABLE>
<CAPTION>
                SIGNATURE                                      TITLE                             DATE
------------------------------------------  -------------------------------------------   -------------------
 
<C>                                         <S>                                           <C>
           /s/ STEVEN GIRGENTI              Chairman of the Board and Chief Executive         August 29, 1997
------------------------------------------  Officer (principal executive officer)
             Steven Girgenti
 
            /s/ STUART DIAMOND              Executive Vice President, Chief Financial         August 29, 1997
------------------------------------------  Officer and Secretary (principal financial
              Stuart Diamond                and accounting officer)
 
        /s/ WILLIAM LESLIE MILTON           Vice Chairman of the Board and President          August 29, 1997
------------------------------------------
          William Leslie Milton
 
            /s/ FRANCIS HUGHES              Director                                          August 29, 1997
------------------------------------------
              Francis Hughes
</TABLE>
 
                                      II-5
[{"type": "S-1", "sequence": "1", "description": "REGISTRATION STATEMENT", "secsgml_size_bytes": 365883}]
{"company-data": {"conformed-name": "HEALTHWORLD CORP", "cik": "0001044993", "assigned-sic": "", "irs-number": "133922288", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-1", "act": "33", "file-number": "333-34751", "film-number": "97673671"}, "business-address": {"street1": "100 AVE OF THE AMERICAS", "city": "NEW YORK", "state": "NY", "zip": "10013", "phone": "2129660077"}, "mail-address": {"street1": "100 AVE OF THE AMERICAS", "city": "NEW YORK", "state": "NY", "zip": "10013"}}
AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON AUGUST 29, 1997
 
                                                     REGISTRATION NO. 333-
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                            ------------------------
 
                                    FORM S-1
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                            ------------------------
                            HEALTHWORLD CORPORATION
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)
DELAWARE                                    7311                                   13-3922288
    (STATE OR OTHER JURISDICTION OF             (PRIMARY STANDARD INDUSTRIAL                    (I.R.S. EMPLOYER
     INCORPORATION OR ORGANIZATION)             CLASSIFICATION CODE NUMBER)                  IDENTIFICATION NUMBER)
------------------------
 
                           100 AVENUE OF THE AMERICAS
                            NEW YORK, NEW YORK 10013
                                 (212) 966-7640
              (ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER,
       INCLUDING AREA CODE, OF REGISTRANT'S PRINCIPAL EXECUTIVE OFFICES)
                            ------------------------
 
                                STEVEN GIRGENTI
               CHAIRMAN OF THE BOARD AND CHIEF EXECUTIVE OFFICER
                            HEALTHWORLD CORPORATION
                           100 AVENUE OF THE AMERICAS
                            NEW YORK, NEW YORK 10013
                                 (212) 966-7640
           (NAME, ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER,
                   INCLUDING AREA CODE, OF AGENT FOR SERVICE)
                            ------------------------
 
                                   Copies to:
HOWARD S. JACOBS, ESQ.                                          EDWARD D. SOPHER, ESQ.
                     ROSENMAN & COLIN LLP                                           STEPHEN E. OLDER, ESQ.
                      575 MADISON AVENUE                                  AKIN, GUMP, STRAUSS, HAUER & FELD, L.L.P.
                NEW YORK, NEW YORK 10022-2585                                         590 MADISON AVENUE

                     TEL: (212) 940-8800                                        NEW YORK, NEW YORK 10022-4616
                     FAX: (212) 940-8776                                             TEL: (212) 872-1000
                                                                                     FAX: (212) 872-1002
------------------------
 
     APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC: As soon as
practicable after the effective date of this Registration Statement.
 
     If any of the securities being registered on this form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, check the following box. / /
 
     If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, check the following box and
list the Securities Act registration statement number of the earlier effective
registration statement for the same offering: / /
 
     If this Form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, check the following box and list the Securities Act
registration number of the earlier effective registration statement for the same
offering: / /
 
     If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box: / /
                            ------------------------
 
                        CALCULATION OF REGISTRATION FEE
AMOUNT TO     PROPOSED MAXIMUM     PROPOSED MAXIMUM
       TITLE OF EACH CLASS OF                BE          OFFERING PRICE     AGGREGATE OFFERING        AMOUNT OF
     SECURITIES TO BE REGISTERED         REGISTERED       PER SHARE(1)           PRICE(1)          REGISTRATION FEE
Common Stock, $.01 par value(2)......     2,415,000           $9.50            $22,942,500            $6,952.27
(1) Estimated solely for the purpose of calculating the registration fee
    pursuant to Rule 457(a) under the Securities Act of 1933.
 
(2) Includes 315,000 shares which may be purchased by the Underwriters to cover
    over-allotments, if any.
                            ------------------------
 
     THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(A) OF
THE SECURITIES ACT OF 1933 OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SECTION 8(A), MAY
DETERMINE.
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
HEALTHWORLD CORPORATION
                             CROSS REFERENCE SHEET
                   PURSUANT TO ITEM 501(B) OF REGULATION S-K
ITEM NUMBER AND
                       HEADING IN FORM S-1                                    LOCATION IN PROSPECTUS
      ------------------------------------------------------  ------------------------------------------------------
1.   Forepart of the Registration Statement and Outside
        Front Cover Page of Prospectus......................  Forepart; Outside Front Cover Page; Inside Cover Page;
                                                                Cross Reference Sheet
 
 2.   Inside Front and Outside Back Cover Pages of
        Prospectus..........................................  Inside Front Cover Page; Additional Information;
                                                                Outside Back Cover Page
 
 3.   Summary Information, Risk Factors and Ratio of
        Earnings to Fixed Charges...........................  Outside Front Cover Page; Prospectus Summary; Risk
                                                                Factors
 
 4.   Use of Proceeds.......................................  Prospectus Summary; Use of Proceeds
 
 5.   Determination of Offering Price.......................  Outside Front Cover Page; Underwriting
 
 6.   Dilution..............................................  Risk Factors; Dilution
 
 7.   Selling Security Holders..............................  *
 
 8.   Plan of Distribution..................................  Outside Front Cover Page; Underwriting
 
 9.   Description of Securities to be Registered............  Description of Capital Stock
 
10.   Interests of Named Experts and Counsel................  Legal Matters; Experts
 
11.   Information with Respect to the Registrant............  Outside Front Cover Page; Prospectus Summary; The
                                                                Consolidation; Risk Factors; Dividend Policy;
                                                                Dilution; Capitalization; Selected Pro Forma
                                                                Combined Financial Information; Selected Financial
                                                                Information of GHB&M and Milton; Management's
                                                                Discussion and Analysis of Financial Condition and
                                                                Results of Operations; Business; Management; Certain
                                                                Relationships and Related Transactions; Principal
                                                                Stockholders; Description of Capital Stock; Shares
                                                                Eligible for Future Sale; Financial Statements
 
12.   Disclosure of Commission Position on Indemnification
        for Securities Act Liabilities......................  *
------------------
* Omitted because answer is not applicable or is negative.
PROSPECTUS                                                 SUBJECT TO COMPLETION
AUGUST 29, 1997
 
                                2,100,000 SHARES
 
                                     [LOGO]
                            HEALTHWORLD CORPORATION
                                  COMMON STOCK
 
                         ------------------------------
 
     Healthworld Corporation (the 'Company') is hereby offering 2,100,000 shares
of its common stock, $.01 par value per share (the 'Common Stock'). It is
currently estimated that the initial public offering price for the Common Stock
will be between $8.00 and $9.50 per share. Prior to the Offering, there has been
no public market for the Common Stock of the Company. See 'Underwriting' for a
discussion of the factors considered in determining the initial public offering
price of the Common Stock. The Company has applied for quotation of the Common
Stock on The Nasdaq National Market under the symbol 'HWLD.'
 
                         ------------------------------
 
        THE COMMON STOCK OFFERED HEREBY INVOLVES A HIGH DEGREE OF RISK.
                    SEE 'RISK FACTORS' BEGINNING ON PAGE 6.
 
                         ------------------------------
 
THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES
   AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR
      HAS THE SECURITIES AND EXCHANGE COMMISSION OR ANY STATE
        SECURITIES COMMISSION PASSED UPON THE ACCURACY OR
           ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION
                         TO THE CONTRARY IS A CRIMINAL OFFENSE.
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
UNDERWRITING
                                          PRICE TO               DISCOUNTS AND              PROCEEDS TO
                                           PUBLIC                COMMISSIONS(1)              COMPANY(2)
Per Share.......................             $                         $                         $
Total(3)........................             $                         $                         $
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 
(1) Excludes a non-accountable expense allowance payable by the Company to

    Unterberg Harris and Pennsylvania Merchant Group Ltd, the representatives
    (the 'Representatives') of the several underwriters (the 'Underwriters'),
    equal to 1% of the gross proceeds of the Offering. The Company has agreed to
    indemnify the Underwriters against certain liabilities, including
    liabilities under the Securities Act of 1933, as amended. See
    'Underwriting.'
 
(2) Before deducting expenses of the Offering payable by the Company, estimated
    at $          .
 
(3) The Company has granted to the Underwriters an option, exercisable within 30
    days after the date of this Prospectus, to purchase up to 315,000 additional
    shares of Common Stock solely to cover over-allotments, if any. If such
    option is exercised in full, the total Price to Public, Underwriting
    Discounts and Commissions and Proceeds to Company will be $          ,
    $          and $          , respectively. See 'Underwriting.'
 
     The shares of Common Stock are offered by the Underwriters, subject to
receipt and acceptance of such shares by them. The Underwriters reserve the
right to reject any order in whole or in part. It is expected that the shares
will be ready for delivery in New York, New York, on or about              ,
1997.
 
                         ------------------------------
 
UNTERBERG HARRIS                                 PENNSYLVANIA MERCHANT GROUP LTD
 
                                           , 1997
[Three page fold out containing the Healthworld name and logo, various
pictures of services provided by the Company and advertising campaigns and
campaign materials prepared by the Company, and the following textual
statements: 'The Company provides a wide array of marketing and communications
services to its clients, ranging from the execution of a discrete marketing
project, such as designing product packaging, to taking responsibility for the
overall marketing message, which enables the Company to incorporate a wide
variety of its services into one integrated marketing campaign' and 'Healthworld
B.V. is a worldwide network of licensed independent marketing and communications
agencies through which the Company utilizes the creative talents of proven
agencies that have expertise and knowledge of particular countries or geographic
regions to develop consistent integrated multinational campaigns for its
clients.']
[CHART DEPICTING FUNCTIONAL STRUCTURE OF THE COMPANY]
 
     CERTAIN PERSONS PARTICIPATING IN THE OFFERING MAY ENGAGE IN TRANSACTIONS
THAT STABILIZE, MAINTAIN OR OTHERWISE AFFECT THE PRICE OF THE COMMON STOCK,
INCLUDING OVER-ALLOTMENT, STABILIZING AND SHORT-COVERING TRANSACTIONS IN SUCH
SECURITIES AND THE IMPOSITION OF A PENALTY BID IN CONNECTION WITH THE OFFERING.
FOR A DESCRIPTION OF THESE ACTIVITIES, SEE 'UNDERWRITING.'
 
     'Healthworld' and the Healthworld logo are registered trademarks for which
the Company holds a license. Trade names and trademarks of other companies

appearing in this Prospectus are the property of their respective holders.
 
                                       2
PROSPECTUS SUMMARY
 
     On the effective date of the Offering made by this Prospectus, Healthworld
Corporation will acquire (the 'Consolidation'), in exchange for shares of its
Common Stock, all of the issued and outstanding common stock of each of
Girgenti, Hughes, Butler & McDowell, Inc. and its affiliated entities ('GHB&M')
and Milton Marketing Group Limited and its subsidiaries ('Milton'). Unless
otherwise indicated, all references herein to the 'Company' include GHB&M and
Milton and give effect to the Consolidation and all references herein to
'Healthworld' refer to Healthworld Corporation prior to the consummation of the
Consolidation. The following summary does not purport to be complete and is
qualified in its entirety by the more detailed information and financial
statements and the related notes appearing elsewhere in this Prospectus. Unless
otherwise indicated, all share, per share and financial information set forth
herein assume no exercise of the Underwriters' over-allotment option. All
statistical and financial information presented in this Prospectus with respect
to Milton has been converted into U.S. Dollars using an exchange rate as of June
30, 1997 of $1.67=pounds 1.00, except as otherwise provided herein and except
for such information contained in or derived from Milton's financial statements
included elsewhere herein. All references herein to industry financial and
statistical information are based on trade articles and industry reports that
the Company believes to be reliable, although there can be no assurance to that
effect.
 
                                  THE COMPANY
 
     The Company is a leading international marketing and communications
services company specializing in health care. The Company provides many of the
world's largest pharmaceutical and other health care companies with a
comprehensive range of integrated strategic marketing services designed to
accelerate the market acceptance of new products and to sustain marketability
throughout their life-cycles. The Company's communications services include
advertising and promotion, publishing, medical education, public relations,
consulting, interactive multimedia, database marketing and marketing research
services. The Company also offers contract sales services which are delivered
through dedicated and syndicated sales teams. The Company offers its clients
global reach and expertise through its operations in the United States and the
United Kingdom, and through Healthworld B.V., a world-wide network of licensed
independent communications agencies located in 12 other countries.
 
     The Company believes that its understanding of the scientific and medical
issues relating to its clients' products and its in-depth knowledge of the
health care industry and regulatory environment are competitive advantages and
are critical for developing the most effective marketing and communications
campaigns and strategies. The Company relies on its creative talent and utilizes
new media and technologies to continually develop better ways to effectively
promote its clients' products. GHB&M, which has consistently been recognized in
the industry as one of the top health care communications agencies, was named
'Agency of the Year' in 1993 and 1996 by Med Ad News, a leading medical
advertising and communications trade publication, and was a finalist for such

award in 1992 and 1994. GHB&M was also named 'Most Creative Agency' by Med Ad
News in 1995. The Company was one of the first companies to develop a
direct-to-consumer marketing ('DTC') campaign for a prescription drug, and
believes it is an industry leader in the development of DTC campaigns, as well
as marketing strategies and campaigns for 'switching' a drug from prescription
to over-the-counter status.
 
     Pharmaceutical and other health care companies have been increasing their
spending on marketing and communications services and, in response to
cost-containment pressures, are increasingly outsourcing certain labor
intensive, high cost services, including marketing and sales and research
functions. Worldwide spending by pharmaceutical and biotechnology companies on
promotional marketing and contract sales is estimated to reach $5.9 billion in
1997. The Company believes that these spending levels will continue to increase
as companies seek to recoup the high costs of product development, maximize
sales, develop brand loyalty and achieve a high market share in the shortest
possible time period due to a limited patent life on new products. In addition,
cost constraints imposed as a result of health care reform and the emergence of
managed care have forced pharmaceutical and other health care companies to spend
more on marketing and communications services to educate the market as to
cost-effectiveness as well as the safety and efficacy of their products.
 
                                       3
Furthermore, the use of DTC to promote prescription drugs has grown rapidly
and is expected to continue to grow in the future. In 1996, the first year in
which more money was spent on DTC than on advertising to physicians,
pharmaceutical companies spent approximately $600 million on DTC, which is twice
as much as was spent in 1995 and almost 10 times more than in 1991. Figures for
the first few months of 1997 suggest that the total may double again and exceed
$1.0 billion for the year.
 
     The Company's contract sales teams form a network of trained professionals
that provides clients with substantial flexibility in selecting the extent and
costs of promoting products as well as such clients' level of involvement in
managing the sales effort. The Company believes that the speed of recruitment,
quality of training and management of sales representatives, supported by
advanced information technology, are key to providing clients with a sales force
tailored to meet their geographic and scheduling needs. Currently, the Company's
contract sales organization operates only in the United Kingdom and provides its
services primarily to consumer products companies, utilities and other
non-health care related companies. In the first quarter of 1997, the Company
began providing contract sales services in the United Kingdom to pharmaceutical
and other health care companies. The Company intends to expand its contract
sales organization into the United States. The Company believes that such
expansion will enable it to complement its existing communications services with
a flexible sales force designed to augment its clients' sales activities.
 
     The Company's strategy is to capitalize on continued growth in marketing
and communications spending by pharmaceutical and other health care companies by
(i) maintaining and enhancing its creative excellence and technical expertise,
(ii) offering its clients a comprehensive range of integrated services, (iii)
continuing to specialize in health care, (iv) increasing its contract sales
services, and (v) further expanding globally. The Company intends to implement

its strategy through internal development and potential acquisitions.
 
     The Company's principal executive offices are located at 100 Avenue of the
Americas, New York, New York 10013. The Company's telephone number is (212)
966-7640.
 
                                  THE OFFERING
Common Stock offered by the Company..........  2,100,000 shares
 
Common Stock to be outstanding immediately
  after the Offering.........................  7,100,000 shares(1)(2)
 
Use of Proceeds..............................  For working capital and general corporate purposes, including
                                               potential acquisitions. See 'Use of Proceeds.'
 
Nasdaq National Market Symbol................  HWLD
------------------
(1) Includes 5,000,000 shares of Common Stock to be issued in connection with
    the Consolidation.
 
(2) Excludes 710,000 shares of Common Stock reserved for issuance upon the
    exercise of stock options which may be granted under the Company's 1997
    Stock Option Plan (the 'Stock Option Plan'), none of which have been granted
    to date. As of the effective date of the Offering, the Company will grant
    options under the Stock Option Plan to purchase up to an aggregate of
    shares of Common Stock, at an exercise price per share equal to the initial
    public offering price. See 'Management--Stock Option Plan.'
 
                                       4
SUMMARY PRO FORMA COMBINED FINANCIAL INFORMATION
 
     The following summary pro forma combined financial information gives effect
to the Consolidation, among other events, as more fully described in 'The
Consolidation,' and should be read in conjunction with the Company's unaudited
Pro Forma Combining Financial Statements and notes thereto, the Combined
Financial Statements of GHB&M and notes thereto, the Consolidated Financial
Statements of Milton and notes thereto and 'Management's Discussion and Analysis
of Financial Condition and Results of Operations' contained elsewhere in this
Prospectus. The Consolidation will be accounted for as a 'pooling of interests.'
Such financial data covers periods when GHB&M and Milton were not under common
control or management and may not be indicative of results that would have been
reported had the Consolidation and the other pro forma adjustments occurred nor
may it be indicative of the Company's future financial position or operating
results.
SIX MONTHS ENDED

                                                                 YEAR ENDED DECEMBER 31,            JUNE 30,
                                                              -----------------------------    ------------------
                                                               1994       1995       1996       1996       1997
                                                              -------    -------    -------    -------    -------
                                                                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
STATEMENT OF INCOME DATA:
Revenues...................................................   $13,081    $16,767    $24,209    $11,322    $14,783
Operating expenses:
  Salaries and related costs...............................     7,890      9,422     15,392      7,525     10,400
  Other operating expenses.................................     3,727      4,904      5,615      2,797      3,000
                                                              -------    -------    -------    -------    -------
                                                               11,617     14,326     21,007     10,322     13,400
                                                              -------    -------    -------    -------    -------
Income from operations.....................................     1,464      2,441      3,202      1,000      1,383
Income before provision for income taxes...................     1,450      2,439      3,133      1,048      1,404
Net income(1)..............................................   $   837    $ 1,401    $ 1,828    $   623    $   820
                                                              -------    -------    -------    -------    -------
                                                              -------    -------    -------    -------    -------
Earnings per share.........................................   $  0.17    $  0.28    $  0.37    $  0.12    $  0.16
                                                              -------    -------    -------    -------    -------
                                                              -------    -------    -------    -------    -------
Shares used in computing earnings per share................     5,000      5,000      5,000      5,000      5,000
JUNE 30, 1997
                                                                                         ---------------------------
                                                                                                        PRO FORMA
                                                                                         PRO FORMA    AS ADJUSTED(2)
                                                                                         ---------    --------------
                                                                                               (IN THOUSANDS)
BALANCE SHEET DATA:
Working capital.......................................................................    $    48        $ 15,953
Total assets..........................................................................     19,916          35,821
Long-term debt, including current portion.............................................      1,324           1,324
Stockholders' equity..................................................................      5,557          21,462
------------------
(1) Immediately upon consummation of the Consolidation, the status of the
    companies comprising GHB&M as 'S Corporations' under Subchapter S of the
    Internal Revenue Code of 1986, as amended (the 'Code'), will terminate. The
    pro forma provision for income taxes reflects a provision for federal income
    taxes as if each of such entities were a 'C Corporation' rather than an 'S
    Corporation' for such periods. See 'The Consolidation.'
 
(2) Gives effect to the Offering at an assumed initial public offering price of
    $8.75 per share and the application of the estimated net proceeds therefrom.
    See 'Use of Proceeds.'
 
                                       5
RISK FACTORS
 
     An investment in the Common Stock offered hereby involves a high degree of
risk and immediate substantial dilution. In addition to the other information
contained in this Prospectus, prospective investors should carefully consider
the following considerations and risks in evaluating an investment in the
Company.
 
     DEPENDENCE ON CERTAIN KEY CLIENTS.  The Company's revenues are highly
dependent upon the advertising, sales and marketing expenditures of
pharmaceutical and other health care companies. Generally, clients are not bound
to an individual marketing and communications company, and any client of the
Company could at any time in the future and for any reason, including a
prolonged economic recession or regulatory problems with respect to a product,
reduce its marketing budget, transfer its business to another agency or take
in-house all or part of the business performed by the Company. The Company
develops long-term relationships with a select group of clients, and a large
portion of its revenues are concentrated among a small number of major clients
which may engage the Company to provide services only for specific products.
However, the Company generally is retained to provide marketing and
communications services with respect to multiple products from each of such
clients, and the loss of business with respect to any one product from any of
such clients would not necessarily affect the Company's business with respect to
other products for which the Company provides its services.
 
     For the year ended December 31, 1996 and the six months ended June 30,
1997, the five largest clients of the Company represented an aggregate of 50%
and 46%, respectively, of the Company's pro forma combined revenues. For the
year ended December 31, 1996, Wyeth-Ayerst Laboratories, Ortho/McNeil
Pharmaceuticals (a division of Johnson & Johnson) and Kraft Jacobs Suchard
Limited accounted for an aggregate of approximately 25%, 9% and 6%,
respectively, of the Company's pro forma combined revenues. For the six months
ended June 30, 1997, Wyeth-Ayerst Laboratories, Ionica plc and Ortho/McNeil
Pharmaceuticals accounted for approximately 18%, 9% and 7%, respectively, of the
Company's pro forma combined revenues. The loss of any of these clients (none of
which has engaged the Company on an exclusive basis) or one or more of the
Company's other clients, the deterioration of the Company's relationships with
any of these clients, a decline in the business of any of such clients or a
decline in such clients' marketing and communications spending (either generally
or with respect to specific products for which the Company is engaged) could
have a material adverse effect on the Company's business, financial condition or
results of operations. See 'Business--Clients' and 'Business--Competition.'
 
     ABSENCE OF COMBINED OPERATING HISTORY.  Although GHB&M and Milton have been
operating in the advertising, marketing and communications industry since April
1986 and August 1978, respectively, and have been working together through their
affiliation with Healthworld B.V. since 1993, Healthworld, which was
incorporated in September 1996, has conducted no operations and generated no
revenues to date. In connection with the Consolidation, Healthworld will enter
into agreements to acquire GHB&M and Milton on the effective date of the
Offering. GHB&M and Milton have been operating as separate independent entities,
and there can be no assurance that the Company will be able to successfully
integrate the operations of these businesses, institute the necessary

Company-wide systems and procedures to successfully manage the combined
enterprise on a profitable basis, or effectively implement its growth strategy.
The unaudited pro forma combining historical financial results of the Company
cover periods when GHB&M, Milton and Healthworld were not under common control
or management and, therefore, may not be indicative of results that would have
been reported by the Company had such events occurred on the dates specified,
nor may they be indicative of the Company's future financial or operating
results. The inability of the Company to successfully integrate GHB&M and Milton
would have a material adverse effect on the Company's business, financial
condition and results of operations and would make it unlikely that the
Company's growth strategy will be successful. See 'The Consolidation,'
'Management's Discussion and Analysis of Financial Condition and Results of
Operations,' the Company's Pro Forma Combining Financial Statements, the
Combined Financial Statements of GHB&M and the related notes thereto, and the
Consolidated Financial Statements of Milton and the related notes thereto.
 
     MANAGEMENT OF GROWTH; ACQUISITION RISKS.  The Company's growth will depend
on a number of factors, including the Company's ability to maintain the high
quality of the services it provides to customers and to increase the number of
services it provides to existing clients, as well as to recruit, motivate and
retain highly skilled creative, technical and marketing personnel. Competition
for highly qualified personnel in the health care
 
                                       6
communications industry is intense and the inability to attract and retain key
personnel could have a material adverse effect upon the Company's business,
results of operations or financial condition.
 
     The Company also intends to grow through the acquisition of businesses
specializing primarily in servicing the pharmaceutical and other health care
industries. Although the Company believes that opportunities for future
acquisitions are currently available, due to considerable acquisitions and
consolidations in the marketing and communications industry in recent years,
increased competition for acquisition candidates exists and may continue in the
future. Consequently, there may be fewer acquisition opportunities available to
the Company as well as higher acquisition prices. There can be no assurance that
the Company will be able to identify, acquire, manage or successfully integrate
acquired businesses without substantial costs, delays or operational or
financial problems. While the Company regularly evaluates and discusses
potential acquisitions, the Company currently has no understandings, commitments
or agreements with respect to any acquisitions. The Company may be required to
obtain additional financing to fund future acquisitions. The Company has no
current commitments or arrangements for such additional financing and there can
be no assurance that the Company will be able to obtain additional financing on
acceptable terms or at all. See 'Management's Discussion and Analysis of
Financial Condition and Results of Operations--Liquidity and Capital Resources'
and 'Business--Strategy.'
 
     FLUCTUATIONS IN QUARTERLY OPERATING RESULTS.  The Company's results of
operations have been and can be expected to be subject to quarterly
fluctuations. Generally, the Company's revenues and profits are lowest in the
first quarter and highest in the fourth quarter. The Company's quarterly revenue
trends result from a number of factors, including, among other things, the

timing of commencement, completion or cancellation of major projects and
industry billing practices which are tied to clients' annual marketing budgets,
while the Company's communications services expenses generally remain constant.
The Company's quarterly results may fluctuate as a result of a number of
additional factors, including delays or costs associated with acquisitions,
government regulatory initiatives and conditions in the health care industry
generally. The Company believes that quarterly comparisons of its financial
results should not be relied upon as an indication of future performance. See
'Management's Discussion and Analysis of Financial Condition and Results of
Operations--Quarterly Operating Results.'
 
     COMPETITION; INDUSTRY CONSOLIDATION.  The health care marketing and
communications industry throughout the United States and Europe is highly
competitive. The Company competes with other marketing and communications firms,
including international and local full-service and specialty marketing and
communications firms and, with respect to contract sales and marketing services,
with in-house sales departments of its clients and other contract sales and
marketing organizations. The Company has in the past and will in the future be
unable to pursue certain marketing and other potential business opportunities
because such opportunities would require the Company to provide services to
direct competitors of existing Company clients.
 
     Consolidation within the pharmaceutical and health care industries as well
as a trend by pharmaceutical and health care companies to allocate outsourcing
of sales, marketing and communications services to fewer organizations, has
heightened the competition among such service providers for a smaller number of
clients. In addition, many of the larger consumer products marketing and
communications companies have acquired health care marketing and communications
companies, which themselves have been increasingly consolidating in recent
years. Many of these companies have substantially greater financial resources,
personnel and facilities than the Company. In addition, if the previously
described consolidation trends continue, the Company may face greater
competition for clients. Although the Company believes it is able to compete on
the basis of the quality of its creative product, service, reputation and
personal relationships with clients, there can be no assurance that the Company
will be able to maintain its competitive position in the industry. See
'Business--Competition.'
 
     EXPANSION OF CONTRACT SALES SERVICES.  Currently, the Company's contract
sales organization operates only in the United Kingdom and provides its services
primarily to consumer products companies, utilities and other nonhealth care
related companies. In March 1997, the Company began providing contract sales
services in the United Kingdom to pharmaceutical and other health care companies
to take advantage of the increased use by such companies in the United Kingdom
of contract sales forces to market their products. In addition, the Company
currently intends to develop a contract sales organization in the United States
to provide contract sales services to pharmaceutical and other health care
companies. The successful expansion of the Company's contract sales operations
in the United Kingdom and in the United States will be dependent on a number of
factors,
 
                                       7
including (i) its ability to effectively compete against the in-house sales

departments of pharmaceutical companies and contract sales organizations
specializing in pharmaceutical and other health care products; (ii) the hiring
and training of qualified management personnel; and (iii) the ability to
integrate such contract sales operations into the Company's current structure.
An inability to manage future growth, compete effectively, or successfully
integrate such contract sales operations could have a material adverse effect on
the Company's business, financial condition or results of operations. See
'Business--Strategy' and 'Business--Competition.'
 
     DEPENDENCE ON KEY PERSONNEL.  The Company is dependent on the efforts and
abilities of its senior management, including Steven Girgenti, its Chairman and
Chief Executive Officer, and William Leslie Milton, its Vice Chairman and
President. The loss of the services of either of Mr. Girgenti or Mr. Milton, or
any other key employee could have a material adverse effect on the Company.
Although the Company intends to obtain key person life insurance on the lives of
Messrs. Girgenti and Milton in the amounts of $4.0 million and $2.0 million,
respectively, as to which the Company will be the sole beneficiary, there can be
no assurance that such policies, if procured, would adequately compensate for
the loss of such individuals. Each of Messrs. Girgenti and Milton and certain
other executive officers of the Company will enter into employment agreements
with the Company upon the consummation of the Consolidation. Each member of the
Company's management and other key employees have or will have executed
confidentiality and non-solicitation agreements that restrict such persons from
misappropriating confidential information during such person's term of
employment and thereafter and from soliciting the Company's clients, prospects
or employees following termination of employment. Notwithstanding such
agreements, in the event of loss of any such personnel there can be no assurance
that the Company would be able to prevent the unauthorized disclosure or use of
its knowledge, practices, procedures or client lists. See 'Management.'
 
     UNCERTAINTY IN HEALTH CARE INDUSTRY AND POSSIBLE HEALTH CARE REFORM.  The
health care industry is subject to changing political, economic and regulatory
influences that may affect pharmaceutical and other health care companies,
particularly with respect to spending by such companies on marketing and
communications services to promote their products. Numerous governments have
undertaken efforts to control growing health care costs through legislation,
regulation and voluntary agreements with medical care providers and
pharmaceutical and other health care product companies. Implementation of
government health care reform may adversely affect marketing expenditures by
pharmaceutical and other health care companies which could decrease the business
opportunities available to the Company. Management is unable to predict the
likelihood of health care reform legislation being enacted or the effects such
legislation would have on the Company. In addition, the success of the Company's
growth strategy depends on its ability to take advantage of certain industry
trends, including continued increases in overall spending levels by
pharmaceutical and other health care companies for marketing and communications
services. Such growth in spending levels has evolved rapidly in recent years and
the Company is unable to predict whether such growth in spending will continue
at present levels or at all. The Company's results of operations could be
materially adversely affected in the event the Company is unable to respond
effectively to the enactment of health care reform legislation or changing
industry trends which may affect future spending levels by pharmaceutical and
other health care companies for marketing and communications services. See
'Business--Industry Background.'

 
     INSURANCE AND POTENTIAL LITIGATION.  The Company, as part of its business,
develops marketing and communications campaigns and materials with respect to
pharmaceutical and other health care products, including newly developed drugs
and other health care products. As a result, the Company may, in the future, be
subject to certain types of litigation, including claims arising from false or
misleading statements made with respect to the use or efficacy of such
pharmaceutical and health care products. Certain of the Company's contracts with
its clients provide for the client to indemnify the Company against such
liabilities. In addition, the Company maintains liability insurance covering
such liabilities, and the Company believes that such liability insurance
coverage is adequate. In certain limited circumstances, however, the Company is
obligated to indemnify its clients with respect to such claims and liabilities.
The Company could be materially and adversely affected if it were required to
pay damages or bear the costs of defending any claim outside the scope of or in
excess of a contractual indemnification provision or beyond the level of
insurance coverage or in the event that an indemnifying party does not fulfill
its indemnification obligations. Even if any such claim was without merit,
defending against such claim could result in adverse publicity and diversion of
management's time and attention and could have a material adverse effect on the
Company.
 
                                       8
CONTROL OF THE COMPANY.  Upon completion of the Consolidation and the
Offering, certain directors and executive officers of the Company will
collectively own approximately 70% of the Company's outstanding Common Stock.
Consequently, such stockholders will be able to control the outcome of matters
submitted to a vote by the Company's stockholders, such as the election of the
Company's Board of Directors, and control the direction and future operations of
the Company. Such concentrations of share ownership may have the effect of
discouraging, delaying or preventing a change in control of the Company. See
'Principal Stockholders.'
 
     DILUTION.  Immediately upon issuance of the Common Stock offered hereby at
an assumed initial public offering price of $8.75 per share, purchasers of the
Common Stock will experience immediate and substantial dilution in the pro forma
net tangible book value per share of Common Stock of $6.24. See 'Dilution.'
 
     FOREIGN EXCHANGE RATE RISKS.  Exchange rates for some local currencies in
countries where the Company currently operates or may operate in the future may
fluctuate in relation to the U.S. Dollar and such fluctuations may have an
adverse effect on the Company's earnings or assets when local currencies are
translated into U.S. Dollars. In particular, because Milton currently operates
only in the United Kingdom, the Company is susceptible to foreign exchange rate
fluctuations between the British Pound Sterling and the U.S. Dollar. Any
weakening of the value of a local currency, including the British Pound
Sterling, against the U.S. Dollar could result in lower revenues and earnings
for the Company when such local currencies are translated into U.S. Dollars.
Therefore, there can be no assurance that currency exchange rates will not have
a material adverse effect on the Company. See 'Management's Discussion and
Analysis of Financial Condition and Results of Operations.'
 
     NO PRIOR MARKET FOR THE COMMON STOCK; DETERMINATION OF OFFERING

PRICE.  Prior to the Offering, there has been no public market for the Common
Stock of the Company. The initial public offering price for the Common Stock
will be determined through negotiations between the Company and the
Representatives based on such factors as the earnings prospects of the Company
and prevailing market conditions, and does not necessarily bear any relationship
to the Company's book value, past operating results or other established
criteria of value. Such price may not be indicative of the market price of the
Common Stock after the Offering has been consummated. The Company has applied
for the listing of the Common Stock on The Nasdaq National Market under the
symbol 'HWLD'. There can be no assurance that an active trading market for the
Common Stock will be established, or if so established, sustained. See
'Underwriting.'
 
     After the Offering, the market price of the Common Stock may be subject to
significant fluctuations in response to numerous factors, including, but not
limited to, variations in the annual or quarterly financial results of the
Company, changes by financial research analysts in their estimates of the
earnings of the Company, conditions in the economy in general or in the
Company's industry in particular, unfavorable publicity or changes in applicable
laws and regulations (or judicial or administrative interpretations thereof)
affecting the Company or the health care communications industry. From
time-to-time, the stock market experiences significant price and volume
volatility, which may affect the market price of the Common Stock for reasons
unrelated to the Company's performance.
 
     SHARES ELIGIBLE FOR FUTURE SALE.  Upon completion of the Offering, there
will be 7,100,000 shares of Common Stock outstanding, of which the 2,100,000
shares sold pursuant to the Offering will be tradeable without restriction by
persons other than 'affiliates' of the Company. The remaining 5,000,000 shares
of Common Stock will be issued in connection with the Consolidation and will be
'restricted' securities within the meaning of the Securities Act of 1933, as
amended (the 'Securities Act'), and may not be sold in the absence of
registration under the Securities Act or an exemption therefrom, including the
exemptions contained in Rule 144 under the Securities Act. No prediction can be
made as to the effect, if any, that future sales of shares of Common Stock will
have on the market price of the Common Stock prevailing from time to time. Sales
of substantial amounts of Common Stock, or the perception that these sales could
occur, could adversely affect prevailing market prices for the Common Stock and
could impair the ability of the Company to raise additional capital through the
sale of its equity securities or through debt financing. The Company and its
officers and directors and the stockholders of GHB&M and Milton have each agreed
to enter into agreements (the 'Lock-up Agreements') under which they will agree
not to offer, sell or otherwise dispose of any shares of Common Stock or other
securities of the Company for a period of 180 days commencing upon the date of
this Prospectus, without the prior written consent of Unterberg Harris, other
than sales or issuances by the Company pursuant to the exercise of the
Underwriters' over-allotment option or pursuant to the grants of stock options
under the Company's 1997
 
                                       9
Stock Option Plan. Thereafter, shares of Common Stock held by the stockholders
of GHB&M and Milton may be sold under Rule 144 under the Securities Act, subject
to the volume, manner of sale and other restrictions of Rule 144. In addition,

the Company has granted to such stockholders unlimited piggy-back registration
rights with respect to such shares, commencing one year from the date of this
Prospectus. See 'Shares Eligible for Future Sale' and 'Underwriting.'
 
     CERTAIN ANTI-TAKEOVER PROVISIONS.  The Company's Certificate of
Incorporation authorizes the Board of Directors of the Company to issue
preferred stock in one or more series with such rights and preferences as may be
determined from time-to-time by the Board of Directors. Accordingly, the Board
of Directors may, without stockholder approval, issue shares of preferred stock
with voting, dividend, liquidation, conversion or other rights which could
adversely affect the voting power or other rights of the holders of Common
Stock. Although the Company does not currently intend to issue any shares of
preferred stock, there can be no assurance that the Company will not do so in
the future. The ability to issue preferred stock as described above, as well as
certain applicable provisions of the Delaware General Corporation Law relating
to business combinations, may have the effect of rendering more difficult,
delaying, discouraging or preventing an acquisition of the Company or change in
control of the Company. See 'Description of Capital Stock.'
 
     ABSENCE OF DIVIDENDS.  The Company has no current intention to pay
dividends on its Common Stock and anticipates that, for the foreseeable future,
working capital and earnings, if any, will be retained to finance the expansion
of its business and for general corporate purposes. See 'Dividend Policy' and
'Description of Capital Stock.'
 
                                       10
THE CONSOLIDATION
 
     Healthworld, which was incorporated in Delaware on September 12, 1996, was
formed to acquire GHB&M and Milton in the Consolidation, and has conducted no
operations to date. Prior to the consummation of the Offering, Healthworld will
enter into separate Agreements and Plans of Organization (the 'Consolidation
Agreements') with the stockholders of GHB&M and Milton pursuant to which, on the
effective date of the Offering, Healthworld will acquire all of the issued and
outstanding stock of each of GHB&M and Milton from the stockholders of GHB&M and
Milton in exchange for an aggregate of 5,000,000 shares of Common Stock of the
Company, at which time GHB&M and Milton will become wholly-owned subsidiaries of
Healthworld. See 'Principal Stockholders.'
 
     The Consolidation will be accounted for as a pooling of interests, which
method of accounting assumes that GHB&M and Milton have been combined from the
Company's inception and restates the historical financial statements for the
Company for the periods prior to the consummation of the Consolidation as though
GHB&M and Milton had been combined from the Company's inception.
 
     Pursuant to the Consolidation Agreements, the stockholders of GHB&M and
Milton will agree not to sell any of the Common Stock to be received by them in
the Consolidation in a 'Private Sale' without first offering to the stockholders
of GHB&M and Milton, respectively, and then to stockholders of Milton and GHB&M,
respectively, a right of first refusal to purchase such shares. Private Sales
are defined to include all transfers other than (i) sales of Common Stock
pursuant to Rule 144 under the Securities Act, (ii) sales pursuant to an
offering registered under the Securities Act, (iii) transfers in connection with

a merger, consolidation or sale of all or substantially all of the assets of the
Company, or (iv) permitted transfers to certain immediate family members and
other relatives. The stockholders of GHB&M and Milton also will agree not to
compete with the Company for a five-year period commencing on the effective date
of the Offering. In addition, members of the Company's management have or will
have entered into agreements pursuant to which they will not compete with the
Company during their employment with the Company and for a certain time period
thereafter. See 'Management--Employment Agreements.'
 
     Prior to the consummation of the Consolidation, the companies comprising
GHB&M (other than Syberactive, Inc. ('Syberactive'), which is treated as a C
Corporation) elected to be treated as S Corporations under the Code, pursuant to
which income or loss of each of such companies was allocated to its stockholders
by inclusion in their respective individual income tax returns. Immediately upon
consummation of the Consolidation, the status of each of the companies
comprising GHB&M as S Corporations will terminate and each of the companies
comprising GHB&M will then be subject to Federal and state income taxes at
applicable corporate rates.
 
     In connection with the termination of the status of each of the companies
comprising GHB&M as S Corporations, GHB&M is currently negotiating to enter into
an agreement which will provide that GHB&M will, prior to the consummation of
the Consolidation, sell approximately $2.5 million of its accounts receivable to
an unaffiliated financial institution at a negotiated discount rate (the
'Accounts Receivable Sale'). Immediately prior to the consummation of the
Consolidation, GHB&M will make distributions (the 'S Corporation Distributions')
to its stockholders of approximately $3.5 million in the aggregate from existing
cash balances for the payment by such stockholders of taxes due on S Corporation
earnings.
 
                                       11
USE OF PROCEEDS
 
     The net proceeds from the sale of the 2,100,000 shares of Common Stock
offered hereby, at an assumed initial public offering price of $8.75 per share,
are estimated to be approximately $15.9 million, after deducting underwriting
discounts and commissions and other estimated expenses payable by the Company in
connection with the Offering (or approximately $18.4 million if the
Underwriters' over-allotment option is exercised in full). The Company intends
to use the net proceeds for working capital and general corporate purposes,
including (i) funding working capital needs which will result from the Accounts
Receivable Sale to be undertaken in connection with the S Corporation
Distributions of approximately $3.5 million, and (ii) for potential
acquisitions. The Company regularly evaluates and discusses potential
acquisitions. While the Company believes that opportunities for future
acquisitions are currently available, it currently has not entered into any
commitment, agreement or understanding with any third party with respect to any
possible acquisition, and there can be no assurance that the Company will be
able to identify or acquire suitable acquisition candidates, or that if
identified such acquisition candidate will be acquired by the Company or
successfully and profitably integrated into the Company. Pending use of the net
proceeds for the foregoing purposes, the Company intends to invest the net
proceeds in short-term, U.S. Dollar denominated, investment grade

interest-bearing securities. See 'The Consolidation,' 'Management's Discussions
and Analysis of Financial Condition and Results of Operations' and
'Business--Strategy--Growth Through Acquisitions.'
 
                                DIVIDEND POLICY
 
     Healthworld has never declared or paid a dividend on its Common Stock. The
companies comprising GHB&M, as S Corporations (other than Syberactive, which is
treated as a C Corporation), made cash distributions on their common stock to
the stockholders of GHB&M of an aggregate of $209,000 in 1995, $1.5 million in
1996, $497,000 through June 30, 1997, and, immediately prior to the consummation
of the Consolidation, will make the S Corporation Distributions of approximately
$3.5 million. The companies comprising Milton made cash distributions on their
common stock to the stockholders of Milton of an aggregate of $101,000 in the
1995 fiscal year, none in the 1996 fiscal year and $55,000 through June 30,
1997.
 
     After the consummation of the Consolidation, the Company intends to retain
all earnings, if any, to finance the expansion of its business and for general
corporate purposes, including future acquisitions, and does not anticipate
paying any cash dividends on its Common Stock for the foreseeable future. Any
future determination to pay cash dividends will be at the discretion of the
Board of Directors and will be dependent on the Company's financial condition,
results of operations, financial requirements and such other factors as the
Board of Directors deems relevant.
 
                                       12
DILUTION
 
     At June 30, 1997, the Company had a pro forma net tangible book value of
$1.9 million, or $0.38 per share of Common Stock. Pro forma net tangible book
value per share is, after giving effect to the Consolidation and the S
Corporation Distributions, the Company's total pro forma tangible assets less
its pro forma total liabilities, divided by the number of shares of outstanding
Common Stock. Pro forma tangible assets are defined as the pro forma assets of
the Company, excluding intangible assets, such as goodwill. After giving effect
to the sale by the Company of 2,100,000 shares of Common Stock offered hereby at
an assumed initial public offering price of $8.75 per share (and after deducting
underwriting discounts and commissions and Offering expenses payable by the
Company), the pro forma net tangible book value of the Company at June 30, 1997
would have been approximately $17.8 million or $2.51 per share. This represents
an immediate increase in pro forma net tangible book value of $2.13 per share to
existing stockholders and an immediate dilution of $6.24 per share to new
investors. Dilution represents the difference between the initial public
offering price paid by purchasers in the Offering and the net tangible book
value per share immediately after completion of the Offering. The following
table illustrates this per share dilution:
Initial public offering price per share......................................            $8.75
  Pro forma net tangible book value per share before the Offering............   $0.38
  Increase in pro forma net tangible book value per share attributable to the

     sale of the Common Stock offered hereby.................................    2.13
                                                                                -----
Pro forma net tangible book value per share after the Offering...............             2.51
                                                                                         -----
Dilution per share to new investors..........................................            $6.24
                                                                                         -----
                                                                                         -----
The following table sets forth, on a pro forma basis as of June 30, 1997,
after giving effect to the Consolidation and the S Corporation Distributions, a
comparison of the number of shares of Common Stock acquired from the Company,
the total consideration paid to the Company and the respective average purchase
price per share paid by existing stockholders and new investors. The following
computations are based on an assumed initial public offering price of $8.75 per
share, before deducting the underwriting discounts and commissions and estimated
Offering expenses payable by the Company.
SHARES PURCHASED       TOTAL CONSIDERATION
                                           --------------------    ----------------------        AVERAGE
                                            NUMBER      PERCENT      AMOUNT       PERCENT    PRICE PER SHARE
                                           ---------    -------    -----------    -------    ---------------
Existing stockholders...................   5,000,000      70.4%    $ 5,557,000(1)   23.2%         $1.11
New investors...........................   2,100,000      29.6%     18,375,000      76.8%          8.75
                                           ---------    -------    -----------    -------
  Total.................................   7,100,000     100.0%    $23,932,000     100.0%
                                           ---------    -------    -----------    -------
                                           ---------    -------    -----------    -------
------------------
(1) Represents the combined stockholders' equity of GHB&M and Milton before the
    Offering. See 'The Consolidation.'
 
                                       13
CAPITALIZATION
 
     The following table sets forth the capitalization of the Company at June
30, 1997, which, pro forma, gives effect to the Consolidation and the S
Corporation Distributions, and pro forma as adjusted, gives effect to the
Consolidation, the S Corporation Distributions and the sale of 2,100,000 shares
of Common Stock offered hereby at an assumed initial public offering price of
$8.75 per share and the application of the estimated net proceeds therefrom. See
'The Consolidation,' 'Use of Proceeds' and 'Selected Pro Forma Financial
Information.' This table should be read in conjunction with the Pro Forma
Combining Financial Statements of the Company and the related notes thereto
included elsewhere in this Prospectus.
JUNE 30, 1997
                                                                    ---------------------------------
                                                                                PRO FORMA
                                                                    ---------------------------------
                                                                    (IN THOUSANDS, EXCEPT SHARE DATA)
Long-term obligations, less current maturities...................                $   582
Stockholders' equity:
  Preferred Stock, $.01 par value, 1,000,000 shares authorized,
     no shares outstanding(1)....................................                     --
  Common Stock, $.01 par value, 20,000,000 shares authorized;
     5,000,000 shares outstanding, pro forma; 7,100,000 shares
     outstanding, pro forma as adjusted(1).......................                     50
  Additional paid-in capital.....................................                  4,581
  Retained earnings..............................................                    926
                                                                                 -------
     Total stockholders' equity..................................                  5,557
                                                                                 -------
     Total capitalization........................................                $ 6,139
                                                                                 -------
                                                                                 -------
JUNE 30, 1997
                                                                    ---------------------------------
                                                                                PRO FORMA
                                                                               AS ADJUSTED
                                                                    ---------------------------------
                                                                    (IN THOUSANDS, EXCEPT SHARE DATA)
Long-term obligations, less current maturities...................               $   582
Stockholders' equity:
  Preferred Stock, $.01 par value, 1,000,000 shares authorized,
     no shares outstanding(1)....................................                    --
  Common Stock, $.01 par value, 20,000,000 shares authorized;
     5,000,000 shares outstanding, pro forma; 7,100,000 shares
     outstanding, pro forma as adjusted(1).......................                    71
  Additional paid-in capital.....................................                20,465
  Retained earnings..............................................                   926
                                                                             ----------
     Total stockholders' equity..................................                21,462
                                                                             ----------
     Total capitalization........................................               $22,044
                                                                             ----------
                                                                             ----------
------------------
(1) Healthworld changed its authorized capital stock on August 13, 1997 to
    21,000,000 shares consisting of 1,000,000 shares of preferred stock, $.01
    par value per share, and 20,000,000 shares of Common Stock, $.01 par value
    per share. See 'Description of Capital Stock.'
 

                                       14
SELECTED PRO FORMA COMBINED FINANCIAL INFORMATION
 
     The following selected pro forma combined financial information gives
effect to the Consolidation, among other events, as more fully described in 'The
Consolidation,' and should be read in conjunction with the Company's unaudited
Pro Forma Combining Financial Statements and notes thereto, the Combined
Financial Statements of GHB&M and notes thereto, the Consolidated Financial
Statements of Milton and notes thereto, and 'Management's Discussion and
Analysis of Financial Condition and Results of Operations' contained elsewhere
in this Prospectus. The Consolidation will be accounted for as a pooling of
interests. The selected pro forma combined statement of income data for the
years ended December 31, 1994, 1995 and 1996 and for the six months ended June
30, 1996 and 1997 and the selected pro forma combined balance sheet data as of
December 31, 1995 and 1996 and June 30, 1997 are derived from the Company's
unaudited Pro Forma Combining Financial Statements included elsewhere herein.
The selected pro forma combined statement of income data for the years ended
December 31, 1992 and 1993, and the selected pro forma combined balance sheet
data as of December 31, 1992, 1993 and 1994, is derived from the Company's
unaudited Pro Forma Combining Financial Statements not included herein. In the
opinion of management, all such financial data includes all adjustments
(consisting of normal recurring adjustments) necessary for a fair presentation
of such data. Such financial data covers periods when GHB&M and Milton were not
under common control or management and may not be indicative of results that
would have been reported had the Consolidation and the other pro forma
adjustments occurred nor may it be indicative of the Company's future financial
or operating results.
SIX MONTHS ENDED
                                                            YEAR ENDED DECEMBER 31,                   JUNE 30,
                                                -----------------------------------------------   -----------------
                                                 1992      1993      1994      1995      1996      1996      1997
                                                -------   -------   -------   -------   -------   -------   -------
                                                               (IN THOUSANDS, EXCEPT PER SHARE DATA)
STATEMENT OF INCOME DATA:
Revenues......................................  $10,569   $11,206   $13,081   $16,767   $24,209   $11,322   $14,783
                                                -------   -------   -------   -------   -------   -------   -------
Operating expenses:
Salaries and related costs....................    6,876     7,554     7,890     9,422    15,392     7,525    10,400
Other operating expenses......................    2,596     3,321     3,727     4,904     5,615     2,797     3,000
                                                -------   -------   -------   -------   -------   -------   -------
                                                  9,472    10,875    11,617    14,326    21,007    10,322    13,400
                                                -------   -------   -------   -------   -------   -------   -------
Income from operations........................    1,097       331     1,464     2,441     3,202     1,000     1,383
Interest expense, net.........................        7         8        14         2        69       (48)      (21)
                                                -------   -------   -------   -------   -------   -------   -------
Income before provision for income taxes......    1,090       323     1,450     2,439     3,133     1,048     1,404
Provision for income taxes(1).................      436       106       613     1,038     1,305       425       584
                                                -------   -------   -------   -------   -------   -------   -------

Net income....................................  $   654   $   217   $   837   $ 1,401   $ 1,828   $   623   $   820
                                                -------   -------   -------   -------   -------   -------   -------
                                                -------   -------   -------   -------   -------   -------   -------
Earnings per share............................  $  0.13   $  0.04   $  0.17   $  0.28   $  0.37   $  0.12   $  0.16
                                                -------   -------   -------   -------   -------   -------   -------
                                                -------   -------   -------   -------   -------   -------   -------
Shares used in computing earnings
  per share...................................    5,000     5,000     5,000     5,000     5,000     5,000     5,000
DECEMBER 31,
                                                ---------------------------------------------------
                                                 1992       1993       1994       1995       1996      JUNE 30, 1997
                                                -------    -------    -------    -------    -------    -------------
                                                                           (IN THOUSANDS)
BALANCE SHEET DATA:
Working capital..............................   $ 2,450    $ 1,835    $ 1,904    $ 3,904    $ 4,132       $    48
Total assets.................................    11,327     13,792     13,848     18,703     22,597        19,916
Long-term debt, including current portion....     1,216        838        662      1,223      1,419         1,324
Stockholders' equity.........................     3,501      2,914      3,880      7,339      8,576         5,557
------------------
(1) Immediately upon the consummation of the Consolidation, the status of the
    companies comprising GHB&M as S Corporations under the Code will terminate.
    The pro forma provision for income taxes reflects a provision for federal
    income taxes as if each of such entities were a C Corporation rather than an
    S Corporation for such periods. See 'The Consolidation.'
 
                                       15
SELECTED FINANCIAL INFORMATION OF GHB&M AND MILTON
 
     The following selected financial information for each of GHB&M and Milton
should be read in conjunction with the Combined Financial Statements of GHB&M
and the notes thereto, the Consolidated Financial Statements of Milton and the
notes thereto, and 'Management's Discussion and Analysis of Financial Condition
and Results of Operations' contained elsewhere in this Prospectus. The selected
combined statement of income data of GHB&M for the years ended December 31,
1994, 1995, 1996 and the selected combined balance sheet data as of December 31,
1995 and 1996 are derived from GHB&M's audited Combined Financial Statements
which are included elsewhere herein. The selected combined statement of income
data of GHB&M for the years ended December 31, 1992 and 1993 and the selected
combined balance sheet data as of December 31, 1992, 1993 and 1994 are derived
from GHB&M's unaudited Combined Financial Statements not included herein, and in
the opinion of management, include all adjustments necessary for a fair
presentation of such data. The selected combined statement of income data of
GHB&M for the six months ended June 30, 1996 and 1997 and the selected combined
balance sheet data as of June 30, 1997 are derived from GHB&M's unaudited
Combined Financial Statements included elsewhere herein which, in the opinion of
management, include all adjustments (consisting of normal recurring adjustments)
necessary for a fair presentation of the combined financial position and results

of operations of GHB&M. The selected consolidated statement of income data of
Milton for the years ended November 30, 1994, 1995 and 1996 and the selected
consolidated balance sheet data as of November 30, 1995 and 1996 are derived
from Milton's audited Consolidated Financial Statements, which are included
elsewhere herein. The selected consolidated statement of income data of Milton
for the years ended November 30, 1992 and 1993 and the selected consolidated
balance sheet data as of November 30, 1992, 1993 and 1994 are derived from
Milton's audited Consolidated Financial Statements not included herein, and in
the opinion of management include all adjustments necessary for a fair
presentation of such data. The selected consolidated statement of income data of
Milton for the seven months ended June 30, 1996 and 1997 and the selected
consolidated balance sheet data as of June 30, 1997 are derived from Milton's
unaudited Consolidated Financial Statements included elsewhere herein which, in
the opinion of management, include all adjustments (consisting of normal
recurring adjustments) necessary for a fair presentation of the consolidated
financial position and results of operations of Milton. The results of
operations of GHB&M for the six months, and of Milton for the seven months,
ended June 30, 1997 are not necessarily indicative of the results for the full
fiscal year.
GHB&M
                             -------------------------------------------------------------------------------------
                                                                (IN THOUSANDS)
                                                                                        SIX MONTHS ENDED
                                         YEAR ENDED DECEMBER 31,                            JUNE 30,
                             -----------------------------------------------   -----------------------------------
                              1992      1993      1994      1995      1996           1996               1997
                             -------   -------   -------   -------   -------   ----------------   ----------------
STATEMENT OF INCOME DATA:
Revenues...................  $ 9,036   $ 9,234   $10,415   $12,368   $14,314       $  6,383           $  7,459
Income from operations.....      991        16     1,088     1,927     2,183            378                991
Net income.................      927        11     1,067     1,816     2,049            423              1,006
DECEMBER 31,
                                                ---------------------------------------------------
                                                 1992       1993       1994       1995       1996      JUNE 30, 1997
                                                -------    -------    -------    -------    -------    -------------
BALANCE SHEET DATA:
Working capital..............................   $ 2,606    $ 1,974    $ 2,455    $ 4,061    $ 4,668       $ 4,680
Total assets.................................    10,264     11,190     12,232     13,287     14,049        14,180
Long-term debt, including current portion....       875        785        587         82        223           176
MILTON
                                               -------------------------------------------------------------------------
                                                                            (IN THOUSANDS)
                                                                                                   SEVEN MONTHS ENDED
                                                           YEAR ENDED NOVEMBER 30,                      JUNE 30,
                                               -----------------------------------------------   -----------------------
                                                1992      1993      1994      1995      1996      1996         1997
                                               -------   -------   -------   -------   -------   -------   -------------
STATEMENT OF INCOME DATA:
Revenues.....................................  $ 1,533   $ 1,972   $ 2,666   $ 4,399   $ 9,895   $ 5,434      $ 8,147
Income from operations.......................      106       315       390       558     1,085       575          308
Net income...................................       64       230       222       316       502       257           29
NOVEMBER 30,
                                                ---------------------------------------------------
                                                 1992       1993       1994       1995       1996      JUNE 30, 1997
                                                -------    -------    -------    -------    -------    -------------
BALANCE SHEET DATA:
Working capital..............................   $  (145)   $  (140)   $   (64)   $  (157)   $  (536)      $(1,132)
Total assets.................................     1,063      2,602      1,681      3,401      6,487         7,300
Long-term debt, including current portion....        92         53         75      1,141      1,196         1,148
16
MANAGEMENT'S DISCUSSION AND ANALYSIS OF
                 FINANCIAL CONDITION AND RESULTS OF OPERATIONS
 
     The following discussion should be read in conjunction with the Company's
unaudited Pro Forma Combining Financial Statements and notes thereto, the
Combined Financial Statements of GHB&M and notes thereto and the Consolidated
Financial Statements of Milton and notes thereto appearing elsewhere herein.

INTRODUCTION
 
     Healthworld has conducted no operations to date and was formed to acquire
all of the outstanding capital stock of GHB&M and Milton in the Consolidation
concurrently with the consummation of the Offering. For a discussion of the
Consolidation and other related events, including the S Corporation
Distributions, see 'The Consolidation.'
 
     The Company conducts all of its operations through GHB&M and Milton. GHB&M,
which is based in New York City, is comprised of the following affiliated
entities: (i) Girgenti, Hughes, Butler & McDowell, Inc. ('GH'), founded in 1986,
which through (x) its GHB&M Division, has been providing traditional advertising
and promotion services and public relations services since 1986, (y) Rubin
Ehrenthal & Associates, a division acquired through a merger with GH in 1991,
specializes in DTC campaigns, and (z) its Data Health Division, organized in
March 1996, provides database marketing services; (ii) Medical Education
Technologies, Inc., organized in 1986, which provides medical education
services; (iii) Syberactive, organized in January 1996, which provides
interactive multimedia services; (iv) Brand Research Corporation, organized in
1992, which provides marketing research services; and (v) Black Cat Graphics,
Inc., organized in 1986, which creates graphic designs and artwork for
advertising and promotion campaigns.
 
     Milton, which is based in the United Kingdom, is comprised of the following
subsidiaries: (i) Milton Marketing Limited ('Milton Marketing'), organized in
1978, which provides traditional advertising and promotion services and
specializes in switching pharmaceutical products from prescription to 'over-the-
counter' status; (ii) Milton Headcount Limited ('Headcount'), originally formed
as a division of Milton Marketing in January 1994, which, along with Effective
Sales Personnel Limited ('ESP'), acquired in November 1995, provides contract
sales services; (iii) Milton Cater Limited ('Milton Cater'), organized in April
1996, which provides public relations services; and (iv) PDM Communications
Limited ('PDM'), acquired in November 1996, which provides direct marketing
services.
 
     The following discussion relating to the pro forma combined historical
financial results of the Company covers periods prior to the Consolidation when
GHB&M and Milton were not under common control or management and, therefore, may
not be indicative of results that would have been reported had the Consolidation
and other pro forma adjustments occurred. Accordingly, the results of operations
for the Company discussed below may not be indicative of future financial or
operating results.
 
GENERAL
 
     The Company is retained by its clients on assignments ranging in duration
from several months to several years. The Company offers a comprehensive range
of integrated services throughout a product's life-cycle, from the development
stage (pre-regulatory approval) to product launch and continuing through the
post-launch stage and, if applicable, such product's switch from prescription to
over-the-counter status.
 
     The Company derives its revenues from fees generated from providing its
communications and contract sales services to its clients. Substantially all

revenues from creative fees are recognized when earned either under monthly
retainer agreements or on an actual time incurred basis. Fees for production are
earned when the production materials are completed. Advance production billings
represent project costs and fees that are billed to clients as projects
progress, and are recognized at completion. Income for field marketing support
is recognized as services are provided. In limited circumstances, the Company
derives revenues through commissions on media and production costs.
 
     Milton operates only in the United Kingdom and, as a result, the Company is
susceptible to foreign exchange rate fluctuations between the British Pound
Sterling and the U.S. Dollar. The Company's financial statements are denominated
in U.S. Dollars, and accordingly, changes in the exchange rate between the
British
 
                                       17
Pound Sterling and the U.S. Dollar will affect the translation of Milton's
financial results into U.S. Dollars for purposes of reporting the Company's
consolidated financial results.
 
RESULTS OF OPERATIONS-THE COMPANY
 
     The Company has provided communications services since 1978 and contract
sales services since January 1994. A significant portion of the Company's growth
in recent years is attributable to the expansion of the Company's contract sales
operations. The following table sets forth pro forma combined revenues for the
Company's communications and contract sales services.
SIX MONTHS ENDED
                                                       YEAR ENDED DECEMBER 31,            JUNE 30,
                                                    -----------------------------    ------------------
                                                     1994       1995       1996       1996       1997
                                                    -------    -------    -------    -------    -------
                                                                      (IN THOUSANDS)
Communications services revenues.................   $12,948    $15,464    $17,632    $ 8,033    $ 8,756
Contract sales services revenues.................       133      1,303      6,577      3,289      6,027
                                                    -------    -------    -------    -------    -------
  Total..........................................   $13,081    $16,767    $24,209    $11,322    $14,783
                                                    -------    -------    -------    -------    -------
                                                    -------    -------    -------    -------    -------
The following table set forth certain pro forma combined income statement
data of the Company expressed as a percentage of revenues for the periods
indicated.
SIX MONTHS
                                                                                           ENDED
                                                         YEAR ENDED DECEMBER 31,         JUNE 30,

                                                        -------------------------     ---------------
                                                        1994      1995      1996      1996      1997
                                                        -----     -----     -----     -----     -----
Revenues............................................    100.0%    100.0%    100.0%    100.0%    100.0%
Operating expenses:
  Salaries and related costs........................     60.3      56.2      63.6      66.5      70.3
  Other operating expenses..........................     28.5      29.2      23.2      24.7      20.3
                                                        -----     -----     -----     -----     -----
                                                         88.8      85.4      86.8      91.2      90.6
                                                        -----     -----     -----     -----     -----
Income from operations..............................     11.2      14.6      13.2       8.8       9.4
Interest expense, net...............................      0.1      --         0.3      (0.5)     (0.1)
                                                        -----     -----     -----     -----     -----
Income before provisions for income taxes...........     11.1      14.6      12.9       9.3       9.5
Provision for income taxes..........................      4.7       6.2       5.3       3.8       4.0
                                                        -----     -----     -----     -----     -----
Net income..........................................      6.4%      8.4%      7.6%      5.5%      5.5%
                                                        -----     -----     -----     -----     -----
                                                        -----     -----     -----     -----     -----
SIX MONTHS ENDED JUNE 30, 1997 COMPARED TO SIX MONTHS ENDED JUNE 30, 1996
 
     Revenues for the first six months of 1997 were $14.8 million, an increase
of $3.5 million, or 30.6%, from $11.3 million for the first six months of 1996.
Of such increase, $2.7 million was attributable to the growth of the Company's
contract sales operations and the remainder was primarily attributable to the
growth of the Company's communications services in the United States, in
particular, advertising and promotion and consulting services.
 
     Salaries and related costs include all compensation and related benefits
for all employees and contracted talent. Salaries and related costs for the
first six months of 1997 were $10.4 million, an increase of $2.9 million, or
38.2%, from $7.5 million for the first six months of 1996. Salaries and related
costs represented 70.3% of revenues in the first six months of 1997, compared to
66.5% in the first six months of 1996. Such increase, as a percentage of
revenues, was primarily attributable to growth of the Company's contract sales
operations and the corresponding increase in labor costs. Generally, labor costs
associated with contract sales operations are greater as a percentage of
corresponding revenues than those for communication services.
 
     Other operating expenses primarily include occupancy, client development
and other related administrative costs. Other operating expenses for the first
six months of 1997 were $3.0 million, an increase of $203,000, or 7.3%, from
$2.8 million for the first six months of 1996. Other operating expenses
represented 20.3% of revenues in the first six months of 1997, compared to 24.7%
of revenues in the first six months of 1996. The decrease in other operating
expenses, as a percentage of revenues, was primarily attributable to such
expenses generally being fixed relative to increases in the Company's revenues.
 
                                       18
Income from operations for the first six months of 1997 was $1.4 million,

an increase of $383,000, or 38.3%, from $1.0 million for the first six months of
1996. Income from operations represented 9.4% of revenues in the first six
months of 1997, compared to 8.8% in the first six months of 1996.
 
     The provision for income taxes for the first six months of 1997 was
$584,000, an increase of $159,000, or 37.4%, from $425,000 for the first six
months of 1996. Such increase was primarily attributable to higher income before
taxes in the first six months of 1997, as compared to the first six months of
1996. The effective tax rate was 41.6% for the first six months of 1997,
compared to 40.6% for the first six months of 1996. The provision for income
taxes reflects a provision for Federal income taxes as if each of the companies
comprising GHB&M were treated as C Corporations rather than S Corporations for
such periods.
 
FISCAL 1996 COMPARED TO FISCAL 1995
 
     Revenues for 1996 were $24.2 million, an increase of $7.4 million, or
44.4%, from $16.8 million for 1995. Of such increase, $5.4 million was primarily
attributable to the internal growth of the Company's contract sales operations
as well as revenues attributable to the operations of ESP (acquired in November
1995), and the remainder was attributable to growth in the Company's
communications services, in particular, advertising and promotion, medical
education and consulting services.
 
     Salaries and related costs for 1996 were $15.4 million, an increase of $6.0
million, or 63.4%, from $9.4 million for 1995. Salaries and related costs
represented 63.6% of revenues in 1996, compared to 56.2% in 1995. Such increase,
as a percentage of revenues, was primarily attributable to the growth of the
Company's contract sales operations and the corresponding increase in labor
costs of such operations, and salaries and other costs related to the
establishment of the Company's public relations business in the United Kingdom.
 
     Other operating expenses for 1996 were $5.6 million, an increase of
$711,000, or 14.5%, from $4.9 million for 1995. Other operating expenses
represented 23.2% of revenues in 1996, compared to 29.2% in 1995. The decrease
in other operating expenses, as a percentage of revenues, was primarily
attributable to such expenses generally being fixed relative to increases in the
Company's revenues.
 
     Income from operations for 1996 was $3.2 million, an increase of $761,000,
or 31.2%, from $2.4 million for 1995. Income from operations represented 13.2%
of revenues in 1996, compared to 14.6% in 1995.
 
     The provision for income taxes for 1996 was $1.3 million, an increase of
$267,000, or 25.7%, from $1.0 million for 1995. Such increase was primarily
attributable to higher income before taxes in 1996, as compared to 1995. The
effective tax rate was 41.7% in 1996, compared to 42.6% in 1995. The provision
for income taxes reflects a provision for Federal income taxes as if each of the
companies comprising GHB&M were treated as C Corporations rather than S
Corporations for such periods.
 
FISCAL 1995 COMPARED TO FISCAL 1994
 
     Revenues for 1995 were $16.8 million, an increase of $3.7 million, or

28.2%, from $13.1 million for 1994. Of such increase, $1.2 million was
attributable to the expansion of the Company's contract sales operations, and
the remainder was attributable to growth in the Company's communications
services, in particular, advertising and promotion, medical education and
publishing services.
 
     Salaries and related costs for 1995 were $9.4 million, an increase of $1.5
million, or 19.4%, from $7.9 million for 1994. Salaries and related costs
represented 56.2% of revenues in 1995, compared to 60.3% in 1994. Salaries and
related costs, as a percentage of revenues, decreased slightly in 1995 due to
improved operating efficiencies.
 
     Other operating expenses for 1995 were $4.9 million, an increase of $1.2
million, or 31.6%, from $3.7 million for 1994. Other operating expenses, which
included additional occupancy costs in 1995, represented 29.2% of revenues in
1995, compared to 28.5% in 1994.
 
     Income from operations for 1995 was $2.4 million, an increase of $977,000,
or 66.7%, from $1.5 million for 1995. Income from operations represented 14.6%
of revenues in 1995, compared to 11.2% in 1994.
 
     The provision for income taxes for 1995 was $1.0 million, an increase of
$425,000, or 69.3%, from $613,000 for 1994. The increase was primarily
attributable to higher income before taxes in 1995, as compared to
 
                                       19
1994. The effective tax rate was 42.6% in 1995, compared to 42.3% in 1994. The
provision for income taxes reflects a provision for Federal income taxes as if
each of the companies comprising GHB&M were treated as C Corporations rather
than S Corporations for such periods.
 
QUARTERLY OPERATING RESULTS
 
     The Company's results of operations have been and are expected to be
subject to quarterly fluctuations. Generally, the Company's revenues and profits
are lowest in the first quarter and highest in the fourth quarter. The Company's
quarterly revenue trends result from a number of factors including, among other
things, the timing of commencement, completion or cancellation of major projects
and industry billing practices which are tied to clients' annual marketing
budgets, while the Company's communications services expenses generally remain
constant. The Company's quarterly results may fluctuate as a result of a number
of additional factors, including delays or costs associated with acquisitions,
government regulatory initiatives and conditions in the health care industry
generally. The Company believes that because of such fluctuations, quarterly
comparisons of its financial results cannot be relied upon as an indication of
future performance.
 
     The following table sets forth, on a quarterly basis, certain pro forma
combining financial information of the Company for the 1995 and 1996 fiscal
years and for the first two quarters of the 1997 fiscal year.
1995                                     1996                           1997
                              -------------------------------------    -------------------------------------    -----------------
                                1ST       2ND       3RD       4TH        1ST       2ND       3RD       4TH        1ST       2ND
                              QUARTER   QUARTER   QUARTER   QUARTER    QUARTER   QUARTER   QUARTER   QUARTER    QUARTER   QUARTER
                              -------   -------   -------   -------    -------   -------   -------   -------    -------   -------
                                                                        (IN THOUSANDS)
Revenues....................  $3,387    $3,910    $4,235    $5,235     $4,705    $6,100    $5,954    $7,450     $6,628    $8,155
Operating expenses:
  Salaries and related
    costs...................   2,131     2,145     2,423     2,723      3,529     3,851     3,716     4,296      5,038     5,362
  Other operating
    expenses................     810     1,147     1,434     1,513      1,372     1,481     1,436     1,326      1,397     1,603
                              -------   -------   -------   -------    -------   -------   -------   -------    -------   -------
                               2,941     3,292     3,857     4,236      4,901     5,332     5,152     5,622      6,435     6,965
                              -------   -------   -------   -------    -------   -------   -------   -------    -------   -------
Income from operations......  $  446    $  618    $  378    $  999     $ (196 )  $  768    $  802    $1,828     $  193    $1,190
                              -------   -------   -------   -------    -------   -------   -------   -------    -------   -------
                              -------   -------   -------   -------    -------   -------   -------   -------    -------   -------
LIQUIDITY AND CAPITAL RESOURCES
 
     GHB&M's cash provided by operations for the six months ended June 30, 1997
was $936,000 and was comprised of net income of $1.0 million and a decrease in
accounts receivable of $2.1 million, partially offset by (i) an increase in
unbilled production charges of $1.8 million, and (ii) an increase in other
assets of $618,000. GHB&M's cash used in investing activities for the six months
ended June 30, 1997 was $157,000 consisting of capital expenditures. GHB&M's
cash used in financing activities for the six months ended June 30, 1997 was
$944,000 and was primarily comprised of S Corporation distributions to
stockholders of $497,000 and the repayment of bank debt of $447,000, in the
aggregate.
 
     Milton's cash used in operating activities for the seven months ended June
30, 1997 was $502,000 and was comprised of (i) an increase in accounts
receivable of $244,000, (ii) an increase in unbilled production charges of
$186,000, (iii) an increase in other current assets and other assets of
$379,000, and (iv) a net decrease in accounts payable and accrued expenses of
$93,000, partially offset by an increase in advance billings of $150,000.
Milton's cash used in investing activities for the seven months ended June 30,
1997 was $72,000, consisting of capital expenditures. Milton's cash provided by
financing activities for the seven months ended June 30, 1997 was primarily
comprised of additional bank overdraft borrowings of $805,000, partially offset
by repayment of bank loans and capital lease obligations of $140,000.
 
     Cash provided by operations of the Company on a combined basis for 1996 was
$3.4 million and primarily consisted of net income for the period of $2.6
million, a reduction in unbilled production charges of $1.6 million, and an
increase in accrued liabilities of $885,000, partially offset by an increase in
accounts receivable of $2.1 million and a reduction in accounts payable of
$394,000. Cash used in investing activities of the Company on a combined basis
for 1996 was $913,000 and was primarily attributable to capital expenditures of
$721,000, the acquisition of PDM and an additional equity interest in Milton

Marketing for an aggregate of $242,000. Cash used in financing activities of the
Company on a combined basis for 1996 was $1.4 million and was primarily
comprised of S Corporation distributions to stockholders of $1.5 million and
repayment of long-term debt and
 
                                       20
capital lease obligations of $66,000, which were partially financed by net
proceeds from line of credit and bank overdraft borrowings of $109,000.
 
     GHB&M's bank borrowings from Chase Manhattan Bank, N.A. (the 'GHB&M Credit
Facility') consist of (i) an uncommitted line of credit (the 'GHB&M Line of
Credit') which expired on July 31, 1997, pursuant to which GHB&M could request
borrowings of, but the bank was not obligated to lend, up to $3.5 million, (ii)
a term note in the principal amount of $300,000 (the 'GHB&M Term Note'), and
(iii) a letter of credit in the amount of $300,000 (the 'GHB&M Letter of
Credit'). The GHB&M Credit Facility is secured by a first security interest in
GHB&M's personal property and is personally guaranteed by certain of GHB&M's
stockholders. The GHB&M Term Note, which was provided to GHB&M to finance the
construction of additional office space, had $176,000 outstanding as of June 30,
1997 and bears interest at 7.75% per annum and is payable in 36 equal monthly
installments with the last installment due February 1999. No amounts were
outstanding under the GHB&M Line of Credit as of its expiration at July 31,
1997. GHB&M is negotiating an extension of the GHB&M Credit Facility as well as
a new revolving credit facility, although no assurance can be given that an
extension will be approved or that a new revolving credit facility will be
available on acceptable terms, or at all.
 
     Milton's borrowings consist of a $672,000 overdraft facility (the 'Milton
Overdraft Facility') with The Bank of Scotland plc, which bears interest payable
at the United Kingdom base rate (7% as of June 30, 1997) plus 2% per annum (the
'Prevailing Rate'). As of June 30,1997, the bank has allowed Milton to exceed
the limit under the Milton Overdraft Facility, and Milton had an outstanding
balance of approximately $1.2 million under the facility at such time. Milton is
currently negotiating with the bank to increase the limit of such facility to
$1,245,000. In addition, as of June 30, 1997, Milton had the following
outstanding indebtedness: (i) a term loan from The Bank of Scotland plc (the
'Milton Term Loan') in the principal amount of $588,000 (of which $407,000 was
outstanding on June 30, 1997), which bears interest payable at the Prevailing
Rate with principal payable in installments of $58,000 each May and November
through November 2000; (ii) a term loan in the principal amount of $456,000 (all
of which was outstanding), which bears interest at the rate of 4% per annum,
originally issued in connection with Milton's acquisition of ESP, and under
which principal is payable in March 1998, and (iii) a term loan from National
Westminster Bank plc in the principal amount of $38,000 ($23,000 of which was
outstanding as of June 30, 1997), which bears interest at 10.5% per annum
payable in monthly installments, with the final payment due in April 1998.
 
     Immediately upon consummation of the Consolidation, the status of the
companies comprising GHB&M (other than Syberactive) as S Corporations will
terminate and GHB&M will then be subject to Federal and state income taxes at
applicable corporate rates. In connection with the termination of the S
Corporation status of such companies, GHB&M is currently negotiating to enter
into an agreement with respect to the Accounts Receivable Sale, which will

provide that GHB&M will, prior to the consummation of the Consolidation, sell
approximately $2.5 million of its accounts receivable to an unaffiliated
financial institution at a negotiated discount rate. Immediately prior to the
consummation of the Consolidation, GHB&M will make the S Corporation
Distributions to its stockholders of approximately $3.5 million in the aggregate
from existing cash balances for payment by such stockholders of income taxes due
on S Corporation earnings. See 'The Consolidation.'
 
     The Company anticipates that capital expenditures for 1997 and 1998 will
total approximately $500,000 and $1.3 million, respectively. Such expenditures
will primarily include spending associated with the expansion of the Company's
New York offices and the acquisition of additional office furniture and computer
equipment.
 
     The Company's primary capital needs after the Offering will be for (i)
funding working capital requirements and general corporate purposes, including
working capital needs which will result from the Accounts Receivable Sale to be
undertaken in connection with the S Corporation Distributions of approximately
$3.5 million, (ii) potential acquisitions, (iii) the repayment of certain
outstanding indebtedness, and (iv) capital expenditures.
 
     The Company believes that cash generated from operations, the net proceeds
received by the Company from the Offering and borrowings under the Company's
credit facilities will be sufficient to fund such capital needs for at least the
next 12 months.
 
                                       21
RESULTS OF OPERATIONS--GHB&M
 
     To date, GHB&M has derived all of its revenues from providing
communications services to its clients.
 
     Revenues for the first six months of 1997 were $7.5 million, an increase of
$1.1 million, or 16.9%, from $6.4 million for the first six months of 1996. This
increase was primarily attributable to growth in GHB&M's communications
services, in particular, advertising and promotion and consulting services.
Income from operations for the first six months of 1997 was $991,000, an
increase of $613,000, or 162.2%, from $378,000 for the first six months of 1996.
Income from operations represented 13.3% of revenues in the first six months of
1997, as compared to 5.9% in the first six months of 1996. The increase in
income from operations, as a percentage of revenues, resulted from an increase
in revenues, partially offset by an increase in operating expenses.
 
     Revenues for 1996 were $14.3 million, an increase of $1.9 million, or
15.7%, from $12.4 million for 1995. This increase was attributable to growth in
GHB&M's communications services, in particular, advertising and promotion,
medical education and consulting services. Income from operations for 1996 was
$2.2 million, an increase of $256,000, or 13.3%, from $1.9 million for 1995.
Income from operations represented 15.3% of revenues in 1996, as compared to
15.6% in 1995.
 
     Revenues for 1995 were $12.4 million, an increase of $2 million, or 18.8%,
from $10.4 million for 1994. This increase was attributable to growth in GHB&M's

communications services, in particular, advertising and promotion, medical
education and publishing services. Income from operations for 1995 was $1.9
million, an increase of $839,000, or 77.1%, from $1.1 million for 1994. Income
from operations represented 15.6% of revenues in 1995, as compared to 10.4% in
1994. The increase in income from operations, as a percentage of revenues,
resulted from an increase in revenues, partially offset by an increase in
salaries and related costs.
 
RESULTS OF OPERATIONS--MILTON
 
     Revenues for the first seven months of fiscal 1997 were $8.1 million, an
increase of $2.7 million, or 49.9%, from $5.4 million for the first seven months
of 1996. Such increase was attributable to the growth of Milton's contract sales
operations, partially offset by a decline in the growth of Milton's
communications services. Income from operations for the first seven months of
1997 was $308,000, a decrease of $267,000, or 46.4%, from $575,000 for the first
seven months of 1996. Income from operations represented 3.8% of revenues for
the first seven months of 1997, compared to 10.6% in the first seven months of
1996. This decline was largely attributable to a reduction in the number of
products approved by the government for 'switching' a drug from prescription to
over-the-counter status. The Company has retained its talent pool in
anticipation of a reversal of such trend. Additionally, losses from the public
relations group added to the overall decline in income from operations. The
Company is in the process of reducing its overhead associated with public
relations to reflect current business activity.
 
     Revenues for 1996 were $9.9 million, an increase of $5.5 million, or
124.9%, from $4.4 million for 1995. Of such increase, $4.9 million was primarily
attributable to the internal growth of Milton's contract sales operations
revenues attributable to the operations of ESP (acquired by Milton in November
1995), approximately $200,000 was attributable to Milton Cater, a joint venture
formed in May 1996, and the remainder was attributable to increased revenues
from Milton's communications services. Income from operations for 1996 was $1.1
million, an increase of $527,000, or 94.4%, from $558,000 for 1995. Income from
operations represented 11.0% of revenues in 1996, compared to 12.7% in 1995.
Such decrease, as a percentage of revenues, was primarily attributable to the
growth of Milton's contract sales operations, which generally have higher labor
costs as a percentage of corresponding revenues than those for communications
services.
 
     Revenues for 1995 were $4.4 million, an increase of $1.7 million, or 65.0%,
from $2.7 million for 1994. Of such increase, approximately $1.0 million was
attributable to the expansion of Milton's contract sales operations, and
approximately $600,000 was attributable to the growth of Milton's communications
services. Income from operations for 1995 was $558,000, an increase of $168,000,
or 43.1%, from $390,000 for 1994. Income from operations represented 12.7% of
revenues in 1995, compared to 14.6% in 1994. Such decrease, as a percentage of
revenues, was primarily attributable to the growth of Milton's contract sales
operations.
 
                                       22
ACCOUNTING STANDARDS
 

     In March 1997, the Financial Accounting Standards Board (the 'FASB') issued
SFAS No. 128, 'Earnings Per Share.' This statement establishes standards for
computing and presenting earnings per share ('EPS'), replacing the presentation
of currently required Primary EPS with a presentation of Basic EPS. For entities
with complex capital structures, the statement requires the dual presentation
for both Basic EPS and Diluted EPS on the face of the statement of earnings.
Under this new standard, Basic EPS is computed based on weighted average common
shares outstanding and excludes any potential dilution; Diluted EPS reflects
potential dilution from the exercise or conversion of securities into common
stock, or from other contracts to issue common stock, and is similar to the
currently required Fully Diluted EPS. SFAS No. 128 is effective for financial
statements issued for periods ending after December 15, 1997, including interim
periods, and earlier application is not permitted. The adoption by the Company
of SFAS No. 128 will have no impact on the Company's reporting of EPS.
 
     In October 1995, the FASB issued SFAS No. 123, 'Accounting for Stock Based
Compensation.' The statement encourages, but does not require, companies to
account for stock compensation awards based on their fair value at the date the
awards are granted. The resulting compensation award would be shown as an
expense on the statement of earnings. Alternatively, the statement allows for
the continued use of Accounting Principles Boards ('APB') Opinion No. 25,
'Accounting for Stock Issued to Employees,' which generally results in no
compensation cost for most fixed stock-option plans, with pro forma disclosure
of net income and earnings per share determined as if the fair value based
method had been applied in measuring compensation cost. The Company will adopt
SFAS No. 123 in fiscal 1997 by continuing to apply the provisions of APB Opinion
No. 25 while providing the required pro forma disclosures as if the fair value
method had been applied.
 
     In March 1995, the FASB issued SFAS No. 121, 'Accounting for the Impairment
of Long-Lived Assets and for Long-Lived Assets to Be Disposed of,' which is
effective for fiscal years beginning after December 15, 1995. SFAS No. 121
requires that long-lived assets be reviewed for impairment whenever events or
changes in circumstances indicate that the carrying amount of the asset in
question may not be recoverable. SFAS No. 121, which was adopted in fiscal 1996,
did not have a material impact on either GHB&M's or Milton's results of
operations, cash flows or financial position.
 
                                       23
BUSINESS
 
     The following presentation contains forward looking statements which
involve risks and uncertainties. The Company's actual results could differ
materially from those anticipated in these forward-looking statements as a
result of certain factors, including those set forth under 'Risk Factors' and
elsewhere in this Prospectus.
 
OVERVIEW
 
     The Company is a leading international marketing and communications
services company specializing in health care. The Company provides many of the
world's largest pharmaceutical and other health care companies with a
comprehensive range of integrated strategic marketing services designed to

accelerate the market's acceptance of new products and to sustain marketability
throughout their life-cycles. The Company's communications services include
advertising and promotion, publishing, medical education, public relations,
consulting, interactive multimedia, database marketing and marketing research
services. The Company also offers contract sales services which are delivered
through dedicated and syndicated sales teams.
 
INDUSTRY BACKGROUND
 
     Pharmaceutical and other health care companies have been increasing their
spending on advertising, marketing and other communications services. Worldwide
spending by pharmaceutical and biotechnology companies on promotional marketing
and contract sales is estimated to reach $5.9 billion in 1997 and to increase by
$1.0 billion by 1999. Additionally, $3.0 billion is spent annually on continuing
medical education. The Company believes that such growth will continue due to a
number of factors, including the following:
 
     NEED TO MAXIMIZE RETURNS ON NEW DRUGS.  In response to the increasing costs
and time required to develop and commercialize a new pharmaceutical product,
pharmaceutical companies implement marketing and communications programs to
achieve rapid market penetration for newly developed products. The cost of
developing a new clinical drug is estimated to be approximately $500 million,
and the research and development process for a new clinical drug, from the
beginning stages of research to obtaining final regulatory approval in the
United States, is estimated to take approximately 12 years. As a result, once a
pharmaceutical company is ready to begin commercial introduction of a newly
developed drug, only approximately five to eight years of patent protection may
remain. In order to recoup their costs of development, maximize sales, develop
brand acceptance and loyalty and achieve a higher market share in the shortest
time period possible, pharmaceutical companies now begin their marketing efforts
for a new drug in its development stage and, upon regulatory approval and
commercialization, continue with sophisticated large-scale advertising and
marketing campaigns.
 
     CHANGES IN THE HEALTH CARE INDUSTRY.  In response to governmental and
market pressures to reduce the cost of health care services and products while
providing such services to a greater portion of the population, the health care
industry has undergone significant changes, including the emergence of managed
care as a primary means for delivery of and payment for such services and
products. Pharmaceutical and other health care companies and providers are being
forced to deliver a greater volume of services and products at reduced costs. In
addition to justifying health care services and products on the basis of safety
and efficacy, pharmaceutical and health care companies and providers must now
also focus increasingly on economic factors and cost-efficiency with respect to
their services and products. As a result, health care companies are spending
more money on marketing and communications services to educate health care
providers, consumers and managed care companies and other third party payor
organizations as to the cost-effectiveness, as well as safety and efficacy, of
their products.
 
     GROWTH OF DIRECT-TO-CONSUMER MARKETING.  During the last five years the use
of direct-to-consumer marketing ('DTC') to promote prescription drugs to
consumers has grown rapidly. Prior to the emergence of DTC, prescription drugs
were promoted almost exclusively to physicians. In 1996, the first year in which

more money was spent on DTC to promote prescription drugs than on advertising to
physicians, pharmaceutical companies spent approximately $600 million on DTC,
which is twice as much as they spent in 1995 and almost 10 times more than in
1991. Figures for the first few months of 1997 suggest that the total may double
again and may exceed $1.0 billion for the year.
 
                                       24
The Company believes that the tremendous growth in DTC in the United States
(DTC is currently prohibited in Europe by governmental regulations) evolved in
response to the increased costs of developing and commercializing new drugs and
the changes brought about by health care reform and managed care, as well as
increased consumer awareness of, and participation in, decisions concerning
health care treatment. As a result, DTC was developed to create brand awareness
and brand loyalty among consumers and to motivate the consumer to specifically
request more information from their physician with respect to a specific brand
of drug to determine its appropriateness for their treatment. In the past, DTC
has been primarily communicated through print media due to regulations imposed
by the United States Food and Drug Administration (the 'FDA') that controlled
the content of television advertisements. In August 1997, the FDA relaxed such
regulations by allowing televised DTC campaigns to promote the benefits of
specific brand-name drugs while only displaying the major side effects and risks
of such drugs in an easily understood format, as compared to the previously
required display of complex and lengthy data. The Company believes that the
relaxation of such FDA regulations will contribute to the rapid growth of DTC,
which the Company expects will continue, and that pharmaceutical companies will
increasingly rely primarily on marketing and communications firms with
particular expertise in DTC of prescription drugs.
 
     INCREASED USE OF OUTSOURCED SALES AND MARKETING SERVICES.  Pharmaceutical
and other health care companies, in response to cost-containment pressures, are
increasingly outsourcing labor intensive, high cost services, including
marketing and sales and research functions. For example, the introduction of a
new drug requires the immediate availability of a large number of specially
trained sales personnel. As a result, pharmaceutical and other health care
companies are increasingly relying on contract sales organizations to assemble,
train and provide them with the largest possible sales force covering numerous
locations to achieve rapid market penetration and increased sales volume.
 
     NEW MEDIA.  Advances in technology are dramatically influencing the
delivery of marketing information. Recent developments in digital technology
such as CD-ROM, the World Wide Web, the Internet, laptop PC presentations and
interactive kiosks are revolutionizing the marketing industry. For example,
interactive multimedia are increasingly being used for patient and physician
education, sales force training and public relations. The Company believes that
pharmaceutical and other health care companies will continue to seek to retain
progressive marketing and communications companies that have the resources and
expertise to develop and incorporate interactive multimedia and other new
technology in their programs and campaigns.
 
     NEED FOR GLOBAL EXPERTISE.  The Company believes globalization is
developing as a result of the recent surge of multinational consolidations in
the pharmaceutical industry, increased foreign protection of intellectual
property, the development of large multi-country trading blocks which may lead

to reduced barriers to foreign commerce, and world-wide access to common
information through the development and use of new media. The Company believes
that in the future, pharmaceutical and other health care companies will seek to
retain marketing and communications firms specializing in health care that have
international reach and experience and are capable of developing multinational
campaigns, or campaigns on a region-by-region basis, with consistent concepts.
 
STRATEGY
 
     The Company's strategy is to capitalize on continued growth in marketing
and communications spending by pharmaceutical and other health care companies by
(i) maintaining and enhancing its creative excellence and technical expertise,
(ii) offering its clients a comprehensive range of integrated services, (iii)
continuing to specialize in health care, (iv) increasing its contract sales
services, and (v) further expanding globally. The Company intends to implement
its strategy through internal development and potential acquisitions.
 
     MAINTAIN AND ENHANCE CREATIVE EXCELLENCE AND TECHNICAL EXPERTISE.  The
Company seeks to recruit the best available creative talent to maintain its
creative excellence. The Company believes that its creative talent enables it to
develop new ways to effectively promote its clients' products. The Company
believes it is an industry leader in the development of DTC campaigns for
prescription drugs as well as marketing strategies and campaigns for 'switching'
a drug from prescription to over-the-counter (non-prescription) status. The
Company was one of the first firms to develop a DTC campaign for a prescription
drug and, currently, the Company has 12 DTC assignments. GHB&M, which has
consistently been recognized in the industry as one of the top health care
 
                                       25
communications agencies, was named 'Agency of the Year' in 1993 and 1996 by Med
Ad News, a medical advertising and communications trade publication, and was a
finalist for such award in 1992 and 1994. GHB&M was also named 'Most Creative
Agency' by Med Ad News in 1995. In addition, the Company maintains a high level
of technological expertise and utilizes new interactive multimedia and other new
technologies in its programs and campaigns.
 
     OFFER A COMPREHENSIVE RANGE OF INTEGRATED SERVICES.  The Company believes
that its clients are continuing to expand their sales and marketing efforts and
require marketing and communications companies that can provide a comprehensive
range of integrated services. The Company's communications services include
advertising and promotion, publishing, medical education, public relations,
consulting, interactive multimedia and database marketing services. The Company
also provides contract sales and marketing research services. Through such
diversification, the Company is able to provide a specific service or cross-sell
multiple services to its clients within a fully integrated campaign. The Company
believes that it will continue to realize significant benefits by capitalizing
on available opportunities which may arise to increase the number of services it
provides.
 
     CONTINUED SPECIALIZATION IN HEALTH CARE.  The Company will continue to
focus on providing its services primarily to pharmaceutical and other health
care companies. The Company believes that its expertise in and understanding of
the business, consumer, scientific, medical and regulatory issues relating to

the health care industry are critical in developing the most effective marketing
campaigns and strategies with respect to pharmaceutical and other health care
products and services. The Company's staff includes physicians, pharmacists,
biologists and other personnel with extensive experience in providing marketing
and communications services to health care companies. The Company intends to
continue to recruit experienced health care and scientific professionals to
ensure that its knowledge base remains up to date.
 
     EXPANSION OF CONTRACT SALES SERVICES.  Pharmaceutical and other health care
companies are increasingly outsourcing certain marketing and sales services to
contract sales organizations. Currently, the Company's contract sales
organization operates only in the United Kingdom and provides its services
primarily to consumer products companies, utilities and other non-health care
related companies. In March 1997, the Company expanded its contract sales
organization in the United Kingdom to enable it to provide services to
pharmaceutical and other health care companies in order to take advantage of the
increased use by such companies in the United Kingdom of contract sales forces
to market their products. The Company intends to expand its contract sales
operations into the United States by the end of the first quarter of 1998 and
anticipates that such operations will focus almost exclusively on pharmaceutical
and other health care products. The Company believes that contract sales will
enable it to complement its existing communications services with a flexible
sales force designed to augment its clients' sales activities.
 
     EXTEND GLOBAL REACH.  The Company believes that pharmaceutical and other
health care companies will increasingly seek to retain marketing and
communications companies with international reach and experience. The Company
believes that it is positioned to address such future demand through its
operations in the United States and the United Kingdom, and through Healthworld
B.V., a world-wide network of licensed independent advertising agencies located
in 12 other countries. Through Healthworld B.V., the Company can utilize the
creative talents of proven agencies that have expertise and knowledge of
particular countries or geographic regions in order to develop consistent and
integrated multinational campaigns for its clients. The Company currently
intends to continue to expand the Healthworld B.V. network and will regularly
evaluate opportunities to expand its business into other international
locations.
 
     GROWTH THROUGH ACQUISITIONS.  The Company intends to pursue acquisitions of
marketing and communications companies specializing in health care in its
existing markets and internationally, including possibly acquiring Healthworld
B.V. licensed agencies. The Company anticipates that it will apply a portion of
the net proceeds of the Offering to undertake such acquisitions if suitable
acquisition candidates are identified. While the Company regularly evaluates and
discusses potential acquisitions, the Company currently has no understandings,
commitments or agreements with respect to any such acquisitions. See 'Risk
Factors-- Management of Growth; Acquisition Risks,' 'Use of Proceeds' and
'Management's Discussion and Analysis of Financial Condition and Results of
Operations.'
 
                                       26
SERVICES
 

     The Company provides a wide array of marketing and communications services
to its clients ranging from the execution of a discrete marketing project, such
as designing product packaging, to taking responsibility for the overall
marketing message, which enables the Company to incorporate a wide variety of
its services into one integrated marketing campaign. The Company seeks to
develop brand loyalty and awareness for its clients at any stage of a product's
life-cycle and approaches each project by carefully evaluating the product, the
client's goals with respect to such product and industry and competitive
considerations.
 
     The services provided by the Company include:
 
  COMMUNICATIONS SERVICES
 
     Advertising and Promotion.  The Company's traditional advertising and
promotion services include developing creative concepts for advertising
campaigns for pharmaceutical and other health care products and applying such
creative concepts to the development and production of a wide variety of
marketing and promotional materials, including medical journal advertisements,
direct mail materials, sales force brochures, hospital displays, convention
exhibit panels, drug sample packages and reminder promotional items. Such
campaigns are targeted almost exclusively to physicians, nurses and other health
care providers and to wholesale distributors. The Company also analyzes
marketing research data, which is either developed by the Company (through
various methods including focus group studies, telephone interview studies and
mailings) or obtained from its clients and other third-party sources, to
determine the most appropriate audience to target as well as the types of
marketing and promotional materials to employ in a campaign.
 
     In response to the rapid growth of DTC during the last five years, the
Company expanded its advertising and promotion services to include DTC. The
Company believes it has become an industry leader in developing DTC campaigns
for prescription drugs, having been one of the first firms to develop such a DTC
campaign. Through a dedicated team engaged exclusively in developing DTC
campaigns, the Company believes it offers more specialized and comprehensive
services to its clients than firms which focus primarily on the promotion of
consumer products generally or on non-DTC advertising and the promotion of
pharmaceutical products.
 
     The Company also believes it is an industry leader in Europe in developing
campaigns for 'switching' a drug from prescription to over-the-counter status.
For example, in the United Kingdom, Regaine (Rogaine in the United States), a
product of Pharmacia & Upjohn, never achieved its sales expectations as a
prescription-only product despite being advertised and promoted to physicians by
other agencies. The Company believed that Regaine's lack of success was
primarily attributable to doctors' skepticism of the drug's effectiveness and a
general perception of hair loss being a cosmetic problem rather than a medical
disorder. In May 1995, the Company presented a comprehensive plan to Pharmacia &
Upjohn that included a new positioning and field marketing program emphasizing
the product's ability to stop further hair loss and relegated the regeneration
of hair to a secondary message. The Company developed and implemented an
integrated media plan which incorporated seven consumer advertisements, special
pharmacist programs (including in-store training manuals and display materials),
and a public relations launch in London.

 
     Publishing.  DTC publications are increasingly being employed as an
additional element of an integrated marketing campaign to promote disease
awareness, understanding of and compliance with treatment, and brand awareness
and loyalty. As part of a DTC campaign developed by the Company for Wyeth-Ayerst
Laboratories' drug Premarin, an estrogen replacement for menopausal women, the
Company developed and publishes Seasons, a bi-monthly magazine for women who are
on Premarin therapy, which is devoted to women's health care issues, including
issues concerning menopause and osteoporosis as well as the efficacy and
benefits of the drug and the means by which it can help improve overall quality
of life. The Company believes that the magazine's current per issue circulation
of 1.0 million Premarin patients makes it one of the most popular women's health
magazines ever published and that the Company's integrated marketing campaign
has contributed to Premarin becoming one of the world's leading drugs in terms
of prescription sales volume.
 
     The Company is seeking to expand its publishing business by offering DTC
publications to pharmaceutical companies as a marketing tool with respect to
drugs used for long term therapy for chronic conditions or illnesses such as
asthma, arthritis, ulcers, heart disease, diabetes and obesity. In addition, the
Company believes that such
 
                                       27
DTC publications can be utilized by insurers and managed care companies as part
of a disease specific management program designed to educate a patient as to his
or her disease, including treatment options and lifestyle advice which may lead
to an overall reduction in the cost of treatment and care.
 
     Medical Education.  The Company develops medical educational programs
targeted primarily to health care providers that are tied closely to the
strategy and marketing goals for its clients, including continuing medical
education programs for which physicians obtain credit and are required to
complete to maintain their licenses. In addition to planning, implementing and
managing symposia, workshops and other conferences that commonly utilize a
multi-disciplinary faculty to address the full spectrum of care on featured
topics, the Company creates newsletters, articles, slide lecture kits and
posters. The Company also assists pharmaceutical and other health care companies
in developing, writing and placing journal articles and supplements, and offers
specialized training programs which incorporate new training technologies that
can be applied in selling pharmaceutical products to non-traditional purchasers,
including managed care organizations and public health officials. The Company
offers such services throughout a product's life-cycle, including prior to
regulatory approval, in order to create awareness and generate interest among
the health care community about such product prior to such approval.
 
     Public Relations.  The Company provides a broad range of public relations
services to its clients, including tactical development, media relations, crisis
management, special events, public sponsorship packages, professional and
patient association liaison, grant and fellowship initiatives, editorial
projects, graphic design and video production. The Company typically integrates
its public relations programs into its overall marketing campaign for a client.
The Company believes that its in-depth knowledge of professional trade and
consumer media and its strong media contacts provide it with ongoing

opportunities to place high impact stories publicizing client products and
services. The Company applies strict journalistic standards to all media contact
initiatives, including the development of news stories, research fact checking
and the production of press materials. In addition, the Company is responsive to
changing regulatory and business climates and works closely with the in-house
regulatory affairs departments and sales organizations of its clients.
 
     Consulting.  The Company's consulting services include strategic planning,
new product development, clinical and regulatory affairs and health economics.
Clients retain the Company to assist them in the development of strategic and
business plans. Typically, the Company investigates and studies the results of
clinical trials and marketing research studies to formulate a strategic
direction for a client's products. The Company may recommend to its clients,
among other things, conducting cost effectiveness clinical studies, extending
patent life protection through line extensions, considering various approaches
to dealing with the FDA, and developing pricing strategies and specific clinical
trials to support certain marketing objectives. The Company currently
subcontracts clinical and regulatory affairs and health economics consulting
services to independent companies specializing in such services. While the
Company is currently considering expanding to provide such regulatory affairs
and health economics consulting services 'in-house,' there can be no assurance
that the Company will, in the future, expand into such services.
 
     Interactive Multimedia.  The Company develops and incorporates interactive
multimedia and other new technologies into its programs and campaigns. The
Company has utilized virtually all existing digital formats, including laser
disc, kiosks, on-line and CD-ROM and owns an extensive archive of over 4,000
medical illustrations which it incorporates in such multimedia formats. The
Company also provides website design and updating, demographics targeting,
statistical measurement and list analysis. The Company believes that interactive
multimedia are particularly attractive to its clients because specific audiences
can be targeted. For example, the Company was retained by Sanofi Winthrop
Pharmaceuticals ('Sanofi') to create an interactive CD-ROM to educate a
specialty group of cardiologists who treat congestive heart failure with respect
to the features and benefits of Primacor. Sanofi believed that Primacor
possessed a novel mechanism of action which most physicians were unaware of or
did not understand. The Company determined that, in addition to the on-going
advertising and sales promotional efforts and the educational programs for the
brand, a CD-ROM program implemented as an educational tool would educate
physicians on the benefits of the brand. The CD-ROM program developed for
Primacor by clinicians presented specific case studies which illustrated the
broad utility and efficacy of Primacor. The interactive nature of CD-ROM allowed
physicians to gain a more comprehensive understanding of Primacor while having
an enjoyable learning experience. A study conducted by Sanofi's
 
                                       28
Marketing Research Department reported that participating doctors praised the
Primacor interactive CD-ROM program as providing an important and valuable
service to the medical community.
 
     In another case, the Company was retained by Hoffmann-LaRoche Inc. to plan
and execute an integrated campaign for the launch of CellCept, a drug developed
to address the problem of organ transplant rejection. The Company's goal was to

develop an effective positioning for the brand that reflected the clinical
profile of the drug and to capture and convey information important to
physicians prescribing the drug, regardless of nationality. The Company's
involvement included naming the drug, developing a logo, conducting marketing
research to assist in creating a strategy, and developing product concepts and a
tactical plan. Since the transplant audience is relatively small and the client
lacked a presence in this closed community, the Company developed CenterSpan, a
restricted access website through which many of the major transplant centers
around the world could be linked in order to exchange data and information on
the drug. The sharing of important information through CenterSpan and the brand
positioning developed by the Company helped CellCept become one of the most
successful product launches in the history of the transplant field and made
Hoffman-La Roche a high-profile company among transplant physicians. The
CenterSpan program has been expanded and is now being run jointly by the
American Society of Transplant Physicians and the American Society of Transplant
Surgeons through a grant provided by Hoffmann-LaRoche.
 
     Database Marketing.  The Company frequently employs database technology in
developing marketing campaigns that are crafted to address a targeted audience.
The utilization by the Company of databases augments the Company's traditional
advertising and promotional services in which it analyzes marketing research
data for target audience profiling and segmentation. The Company utilizes its
own or its clients' databases as well as databases it leases from third parties
(including the American Medical Association). Through its direct marketing
division, the Company developed and manages a database of 1.5 million patients
generated from current and former patient readers per issue of Seasons. The
Company regularly evaluates other mechanisms that may enable it to collect data
to evaluate the effectiveness of its clients' marketing campaigns.
 
     Marketing Research.  The Company develops and offers its clients
specialized research programs to measure the 'return on investment' ('ROI') of
its DTC and other marketing programs. The ROI model utilized by the Company is a
proprietary model based on a consumer products research methodology that has
been adapted and modified for use with respect to prescription drugs. Through
the use of its ROI model, the Company has established normative data that it
will use as benchmarks for future ROI studies. The Company believes that data
from such programming assists the Company and its clients in determining the
most effective means of marketing a particular product.
 
  CONTRACT SALES SERVICES
 
     The Company offers a flexible range of contract sales services which are
delivered through dedicated and syndicated sales teams. The Company's contract
sales teams form a network of trained professionals that provides clients with
substantial flexibility in selecting the extent and costs of promoting products
as well as the clients' level of involvement in managing the sales effort.
Dedicated sales teams are comprised of sales representatives recruited by the
Company in accordance with client specifications to conduct sales efforts for a
particular client. Dedicated sales teams can be managed by the Company or can
report directly to the client, depending on client preference. Syndicated sales
teams promote a number of products for different clients and are generally
managed directly by the Company.
 
     The Company believes that speed of recruitment, quality of training and

management of sales representatives, supported by advanced information
technology, are key to providing clients with a sales force tailored to meet
their geographic and scheduling needs. The Company's ability to assemble a sales
team quickly is a product of combining the talents of experienced personnel for
screening and interviewing candidates with the use of information technology,
such as scanning and resume tracking systems, to expedite recruitment. The
Company believes that it can recruit client-specific national sales force in as
few as eight to 12 weeks, depending on the assignment, whereas the Company
believes pharmaceutical and other health care product companies often take six
to nine months to build an internal sales force. Sound hiring procedures,
including background screenings and drug testing programs, supplemented by the
Company's internal training and development programs, help to ensure the quality
of recruited personnel.
 
                                       29
Currently, the Company provides its contract sales services in the United
Kingdom primarily to consumer product companies, utilities and other non-health
care related companies. The Company's contract sales organization, Headcount,
currently is the fifth largest contract sales company in the United Kingdom. The
Company hires sales personnel on a project-by-project basis, with the actual
number of representatives retained contingent upon a particular assignment. The
Company maintains a database listing approximately 5,000 sales personnel, and
typically employs, either on a part-time or full-time basis, approximately 1,000
sales persons at any given time.
 
     In March 1997, the Company expanded its contract sales organization in the
United Kingdom to enable it to provide contract sales services to pharmaceutical
and other health care product companies. In addition, the Company currently
intends to begin providing contract sales services in the United States by the
end of the first quarter of 1998. The Company anticipates that its contract
sales operations in the United States will focus almost exclusively on
pharmaceutical and other health care products and services.
 
HEALTHWORLD B.V.
 
     In August 1993, the Company organized Healthworld B.V., a world-wide
network of licensed independent marketing and communications agencies, in
response to the Company's belief that pharmaceutical and other health care
companies will increasingly seek to retain marketing and communications
companies with international reach and experience. Healthworld B.V. enables the
Company to utilize the creative talents of proven agencies that have expertise
and knowledge of particular countries or geographic regions to develop
consistent and integrated multinational campaigns for its clients.
 
     Healthworld B.V. currently consists of 12 licensed independent
communications agencies (other than the Company) located in Belgium, Canada,
Denmark, Finland, France, Holland, Hungary, Italy, Norway, South Africa, Spain,
Sweden, the United Kingdom and the United States. Each member agency has entered
into a license agreement with Healthworld B.V. which provides, among other
things, that such agency will perform services for the clients of any other
member agency upon request by such other member agency.
 
     Although to date Healthworld B.V. has not contributed materially to the

Company's results of operations, the Company believes that Healthworld B.V. has
enabled the Company to attract additional clients based upon the Company's
ability to offer global reach and expertise.
 
CLIENTS
 
     The Company currently services approximately 45 clients. The Company's
clients are primarily pharmaceutical and other health care companies, including
health care service providers and manufacturers of diagnostic equipment, medical
equipment, medical devices and medical supplies. The Company's major clients
include five of the top ten pharmaceutical companies in the world today based on
global market share. The Company currently provides its contract sales services
in the United Kingdom primarily to consumer products companies, utilities and
other non-health care related companies. In 1996, the following clients of the
Company represented $300,000 or more of the Company's pro forma combined
revenues:
 
Alza Pharmaceuticals
Applied Microbiology, Inc.
Eli Lilly & Company
Forest Laboratories
The Hospital Saving Association
Johnson & Johnson Clinical Diagnostics
Kimberly-Clark Limited
Kraft Jacobs Suchard Limited
The Liposome Company
Muro Pharmaceuticals, Inc.
Ortho/McNeil Pharmaceuticals (a division of
  Johnson & Johnson)
Roche Laboratories
Sanofi Winthrop Pharmaceuticals
SmithKline Beecham Pharmaceuticals
Whitehall, Inc
Wyeth-Ayerst Laboratories
 
     Clients are not generally bound to an individual agency and may move their
accounts at any time from one agency to another. In addition, clients generally
tend to use more than one agency for their marketing requirements. The Company's
ability to compete for new advertising clients and assignments is limited by the
 
                                       30
Company's general practice (and the practice followed by many advertising
agencies) of not representing more than one client with competing product lines.
 
INTELLECTUAL PROPERTY
 
     In 1997, the Company entered into a 50-year license agreement (the 'License
Agreement') with Healthworld B.V. pursuant to which Healthworld B.V. granted the
Company rights to use the 'Healthworld' and 'Healthworld Communications'
trademarks, the tradename 'Healthworld,' and the Healthworld logo, for $1.00 per
year. Under the License Agreement, Healthworld B.V. must obtain the Company's
prior written consent before further licensing such licensed property.
Healthworld B.V. has trademarks registered with the United States Patent and

Trademark Office for the words 'Healthworld' and 'Healthworld Communications'
which expire in March 2004 and for the Healthworld name together with its logo
which expires in May 2005. Healthworld B.V. also has trademarks registered or
applications for such registrations pending for the tradename 'Healthworld' and
the Healthworld logo in the United Kingdom and in each of the other countries in
which licensed Healthworld B.V. agencies are located, as well as several other
countries. The Company considers all of such United States and United Kingdom
trademarks to be material to its operations.
 
COMPETITION
 
     The health care marketing and communications industry throughout the United
States and Europe is highly competitive. The Company competes with many other
marketing and communications firms, including international and regional
full-service and specialty marketing and communications firms. Consolidation
within the pharmaceutical and health care industries as well as a trend by
pharmaceutical and health care companies to limit outsourcing of sales,
marketing and communications services to fewer organizations has heightened the
competition among such service providers for a smaller number of clients. In
addition, many of the larger consumer product marketing and communications
companies have acquired specialty health care marketing and communications
companies, which themselves have been increasingly consolidating in recent
years. For instance, each of Bozell, Jacobs, Kenyon & Eckhardt, Grey
Advertising, Interpublic Group, Omnicom Group, Inc., Saatchi & Saatchi
Advertising Affiliates Holdings, Inc. and Young & Rubicam, Inc., has one or more
divisions specializing in health care marketing and communications. Many of
these companies have substantially greater financial resources, personnel and
facilities than the Company. If the previously described consolidation trends
continue, the Company may face greater competition for its clients and for
acquisition candidates. Although the Company believes it is able to compete on
the basis of the quality of its creative product, service, reputation and
personal relationships with clients, there can be no assurance that the Company
will be able to maintain its competitive position in the industry.
 
     With respect to contract sales services provided to consumer products
companies in the United Kingdom, the Company currently competes against in-house
sales departments of such companies and contract sales organizations operating
in the United Kingdom, many of which are larger and have substantially greater
financial resources. With respect to contract sales services targeted to
pharmaceutical and medical devices, the Company currently competes in the United
Kingdom, and, if such services are expanded into the United States, will compete
in the United States, against the in-house sales departments of pharmaceutical
companies and local contract sales organizations specializing in pharmaceutical
and medical device products. The primary competitive factor affecting contract
sales and marketing services is the ability to quickly assemble, train and
manage large qualified sales forces to handle broad scale sales campaigns. The
Company believes that it competes favorably in these areas in the United Kingdom
with respect to its non-health care related contract sales services. However,
with respect to health care related contract sales services, there can be no
assurance that the Company will compete favorably in these areas in the United
Kingdom or in the United States.
 
     While there are relatively low barriers to entry into the marketing and
communications industry as a whole, the Company believes that its specific

expertise with respect to the pharmaceutical and health care industry
distinguish it from prospective competitors attempting to develop health care
communications businesses. Notwithstanding the Company's expertise, it expects
that it will face additional competition from new entrants into the industry in
the future. There can be no assurance that existing or future competitors will
not develop or offer marketing communications services and products that provide
significant performance, creative, technical or other advantages over those
offered by the Company.
 
                                       31
GOVERNMENT REGULATION
 
     While there are no laws that specifically regulate the health care
communications industry, the health care and pharmaceutical industries are
generally subject to a high degree of government regulation, and the trend is
toward regulation of increasing stringency. Federal, state and local laws and
regulations affect the permissible form, content and timing of marketing
activities involving pharmaceutical and other health care products. Some of
these laws relate to general considerations such as truthfulness, comparative
advertising and the relative responsibilities of clients and advertising firms.
Other laws, such as the Food, Drug and Cosmetics Act and the anti-fraud and
abuse laws and regulations affecting the Medicare, Medicaid and other
governmental health care programs, regulate the form, content and/or timing of
marketing activities involving pharmaceutical and other health care products,
including the permissible activities the Company may undertake to develop
markets for its clients' products. The Company has implemented a rigorous review
process, emphasizing the importance of compliance with regulatory matters. In
addition, the Company's clients generally follow a rigorous internal review
process.
 
PROPERTIES
 
     The Company maintains corporate headquarters in New York in a leased
facility which occupies approximately 44,600 square feet of office space. The
lease for such office space is due to expire on December 31, 2009 and has
escalating rent currently at the base rate of $575,000 per annum which will
increase to $662,000 per annum in December 1997, $750,000 per annum in December
1998 and $970,000 per annum from December 2003 through the expiration of the
lease. The Company also leases small offices in Bellmore, New York and Chicago,
Illinois.
 
     The Company leases approximately 2,850 square feet of office space in
London for its United Kingdom headquarters and approximately 5,218 square feet
of office space in Chertsey for its contract sales operations. The Company also
leases small offices located in Brighton and in two locations in each of
Berkshire and Surrey. The aggregate annual base rent for all of the Company's
United Kingdom facilities is approximately $393,000.
 
     The Company believes that its existing facilities are adequate to meet its
current operating needs and that suitable additional space should be available
to the Company on reasonable terms should the Company require additional space
to accommodate future operations or expansion.
 

EMPLOYEES
 
     As of August 1, 1997, the Company had four part-time employees and
approximately 190 full-time employees, 110 of which were employed in the
Company's United States operations and 80 of which were employed in the
Company's United Kingdom operations, excluding sales persons employed in the
Company's contract sales organization. In the United Kingdom, the Company
typically employs approximately 1,000 sales persons for its contract sales
organization at any given time, and such sales persons are employed both on a
full-time and part-time basis. The Company is not a party to any collective
bargaining agreement and the Company's employees are not represented by any
labor union. The Company considers its relationship with its employees to be
good. The Company's success depends in large part, upon its ability to attract,
develop, motivate and retain highly skilled creative and technical employees, of
which there can be no assurance.
 
LEGAL MATTERS
 
     The Company is not a party to any pending litigation which, if decided
adversely to the Company, would have a material adverse effect on the business,
financial condition or results of operations of the Company, and the Company is
not aware of any material threatened litigation which might involve the Company.
 
                                       32
MANAGEMENT
 
DIRECTORS AND EXECUTIVE OFFICERS
 
     The following table sets forth information concerning the Company's
directors and executive officers and those persons who will become directors
(each, a 'Director Nominee') immediately upon consummation of the Consolidation.
NAME                                               AGE   POSITION
------------------------------------------------   ---   ------------------------------------------------
Steven Girgenti.................................   51    Chairman of the Board and Chief Executive
                                                           Officer
William Leslie Milton...........................   53    Vice Chairman of the Board and President
Stuart Diamond..................................   36    Executive Vice President, Chief Financial
                                                           Officer and Secretary
William Butler..................................   52    President--Global Communications Services
Herbert Ehrenthal...............................   61    President--U.S. Communications Services
Francis Hughes..................................   59    Chief Creative Officer and Director
Michael Garnham.................................   42    Managing Director--Headcount
Peter Knight(1)(2)..............................   46    Director
Colin Lloyd(1)(2)(3)............................   55    Director
Jonah Shacknai(1)(2)(3).........................   40    Director
Alex Spizz(1)(3)................................   49    Director
------------------

(1) Director Nominee.
 
(2) Will become a member of the Compensation Committee immediately upon
    consummation of the Consolidation.
 
(3) Will become a member of the Audit Committee immediately upon consummation of
    the Consolidation.
 
     Directors are elected annually. Each director holds office until the next
annual meeting of stockholders, or until his successor has been elected and
qualified. Executive officers are ordinarily elected annually and serve at the
discretion of the Board of Directors. See '--Employment Agreements' for a
description of certain employment agreements of executive officers.
 
     STEVEN GIRGENTI has served as Chairman of the Board and Chief Executive
Officer of the Company since August 1997. Mr. Girgenti co-founded GH in April
1986 and has served as its President and Chief Executive Officer since then.
Beginning in 1969, Mr. Girgenti worked in the pharmaceutical industry for
advertising companies specializing in medical communications, including William
Douglas McAdams. Prior to that, Mr. Girgenti held a variety of positions with
pharmaceutical companies, including Director of Marketing Research and Product
Manager for DuPont Pharmaceuticals and Manager of Commercial Development for
Bristol-Myers Squibb Company.
 
     WILLIAM LESLIE MILTON has served as Vice Chairman of the Board and
President of the Company since August 1997. Mr. Milton founded Milton Marketing
Limited in 1979 and has served as its Chairman of the Board and Chief Executive
Officer since such time. Prior to 1979, Mr. Milton held a variety of positions
with WarnerLambert Consumer Healthcare, Beecham Laboratories (South Africa),
Gillette Industries UK Limited, and Parke Davis Pty (South Africa) where he
developed an expertise in marketing management with respect to medical and
consumer health care products.
 
     STUART DIAMOND has served as Executive Vice President, Chief Financial
Officer and Secretary of the Company since August 1997. Mr. Diamond was the Vice
President-Controller of the Licensing Division of Calvin Klein Inc., an apparel
company, from April 1996 to August 1997. He was the Vice President and Chief
Financial Officer of Fenway Partners Inc., a leveraged buyout firm, from April
1995 to April 1996. Mr. Diamond was the Senior Vice President and Chief
Financial Officer of Medicis Pharmaceutical Corp., a publicly traded
pharmaceutical company, from 1990 to April 1995.
 
                                       33
WILLIAM BUTLER will become President of the Company's Global Communications
Services upon consummation of the Consolidation. Mr. Butler has been President
and Chief Operating Officer of the GHB&M Division of GH. Mr. Butler co-founded
GH in April 1986 and has served as its Executive Vice President since such time.
Mr. Butler has worked for various medical communications firms, including Sudler
& Hennessey and William Douglas McAdams. Prior to that time, Mr. Butler worked
in a number of marketing positions at Pfizer Inc. and Continental Group.
 
     HERBERT EHRENTHAL will become President of the Company's U.S.
Communications Services upon consummation of the Consolidation. Mr. Ehrenthal

has been President and Chief Operating Officer of Rubin Ehrenthal & Associates,
a division of GH, since 1991 when Rubin, Reid, Noto & Ehrenthal, Inc. ('Rubin
Ehrenthal') (of which he was a founding member) merged with GH. Prior to his
employment with Rubin Ehrenthal, Mr. Ehrenthal held a variety of senior
management positions with various advertising agencies, including BBDO Worldwide
Inc. and Ted Bates.
 
     FRANCIS HUGHES has been a director of the Company since August 1997 and
will become Chief Creative Officer of the Company upon consummation of the
Consolidation. Mr. Hughes co-founded GH in April 1986 and has served as its
Secretary since then. In 1980, Mr. Hughes co-founded William J. Bologna
International, Inc., a health care communications company. Prior to that time,
Mr. Hughes worked in the medical divisions of various advertising companies,
including J. Walter Thompson Co., Compton and William Douglas McAdams.
 
     MICHAEL GARNHAM has been the Managing Director of Headcount since August
1993. Prior to August 1993, Mr. Garnham was the Associate Director of FMCG Field
Marketing Ltd., a field marketing company.
 
     PETER KNIGHT will become a director of the Company upon consummation of the
Consolidation. Mr. Knight has been a partner of the law firm of Wunder, Knight,
Levine, Thelen & Forsey since 1991. He was General Counsel and Secretary of
Medicis Pharmaceutical Corp. from 1989 to 1991. Mr. Knight is currently a
director of Comsat Corp., an international telecommunications and network
service company, Medicis Pharmaceutical Corp. and Whitman Education Group Inc.,
a private for-profit education company.
 
     COLIN LLOYD will become a director of the Company upon consummation of the
Consolidation. Mr. Lloyd has been the Chief Executive Officer of Direct
Marketing Association (U.K.) Ltd., a direct marketing trade association, since
September 1993. Mr. Lloyd served as a consultant to and a director of various
companies from 1992 to 1993, and was President of Marketing Services Worldwide
of Roux, Seguile, Cyzak & Goudard, SA ('RSCG'), an international advertising
group, from February 1990 to August 1991. In 1969, Mr. Lloyd co-founded KLP
Group plc ('KLP'), a sales promotion and marketing services company in the
United Kingdom in which he served as the Chief Executive Officer until August
1991. KLP was acquired in 1990 by RSCG.
 
     JONAH SHACKNAI will become a director of the Company upon consummation of
the Consolidation. Mr. Shacknai has been Chairman of the Board and Chief
Executive Officer of Medicis Pharmaceutical Corp. since 1988. From 1982 to 1988,
Mr. Shacknai was a senior partner in the law firm of Royer, Shacknai, and Mehle,
where he represented over 34 multinational pharmaceutical and medical device
companies. From 1983 to 1986, Mr. Shacknai was also an executive officer of Key
Pharmaceutical, Inc., prior to its acquisition by Schering-Plough Corp. From
1977 to 1982, Mr. Shacknai served as Chief Aide to a United States House of
Representatives committee with responsibility for health policy. Mr. Shacknai
serves as a member of the National Arthritis and Musculoskeletal and Skin
Diseases Advisory Council of the National Institute of Health, and the
U.S.-Israel Science and Technology Commission.
 
     ALEX SPIZZ will become a director of the Company upon consummation of the
Consolidation. For more than the past five years, Mr. Spizz has been a senior
member of the law firm of Todtman, Young, Nachamie, Hendler & Spizz, P.C.,

counsel to the Company, GHB&M and Healthworld B.V. in connection with the
Consolidation and other corporate matters.
 
COMMITTEES OF THE BOARD
 
     Upon consummation of the Offering, the Board of Directors will establish an
Executive Committee, Compensation Committee and Audit Committee. The Executive
Committee will be entrusted with the authority to exercise the powers of the
Board of Directors between meetings of the Board of Directors. The Compensation
Committee will review and recommend to the Board of Directors the compensation
and benefits of all officers of
 
                                       34
the Company, review general policy matters relating to compensation and benefits
of employees of the Company and administer the issuance of stock options to the
Company's officers, employees, directors and consultants. The Audit Committee
will be responsible for recommending annually to the Board of Directors the
independent auditors to be retained by the Company, and will meet with
management and the Company's independent auditors to determine the adequacy of
internal controls and other financial reporting matters.
 
EXECUTIVE COMPENSATION
 
     Healthworld, which was incorporated on September 12, 1996 and has conducted
limited operations and generated no revenues to date, did not pay any
compensation to its executive officers in 1996. The following table sets forth
the cash compensation paid by GHB&M for the fiscal year ended December 31, 1996,
and by Milton for the fiscal year ended November 30, 1996, to the Chief
Executive Officers of each of GHB&M and Milton, respectively, and to each of the
four other most highly compensated executive officers of GHB&M and Milton whose
cash compensation exceeded $100,000 for such respective fiscal years.
 
                           SUMMARY COMPENSATION TABLE
ANNUAL COMPENSATION
                                                         -------------------------------------
                                                                                OTHER ANNUAL          ALL OTHER
NAME AND PRINCIPAL POSITION                              SALARY($)   BONUS($)  COMPENSATION($)     COMPENSATION($)
-------------------------------------------------------  -------     -------   ---------------     ---------------
Steven Girgenti
  Chairman of the Board and
  Chief Executive Officer..............................    --          --         $ 337,000(1)        $ 981,500(2)
William Leslie Milton
  Vice Chairman of the Board and President.............  $98,280(3)(4)   --       $  32,340(3)(5)       --
William Butler
  President--Global Communications Services............    --          --         $ 275,000(1)        $ 222,622(2)
Herbert Ehrenthal
  President--U.S. Communications Services..............    --          --         $ 275,000(1)        $ 231,211(2)
Francis Hughes
  Chief Creative Officer...............................    --          --         $ 225,000(1)        $  52,372(2)

Michael Garnham
  Managing Director--Headcount.........................  $92,301(3)    --           --                $  45,864(3)(6)
------------------
(1) Represents consulting fees paid by certain of the companies comprising GHB&M
    to certain companies wholly-owned by each respective officer.
 
(2) Represents distributions made to such individuals by certain of the
    companies comprising GHB&M. A portion of such distributions were made to
    cover each individual's 1995 and estimated 1996 tax liabilities associated
    with the election of the companies comprising GHB&M to be treated as S
    Corporations (other than Syberactive, which was treated as a C Corporation)
    during such periods.
 
(3) Calculated using the 1996 average exchange rate of $1.56 = pounds 1.00.
 
(4) Compensation paid by Milton Marketing.
 
(5) Includes (i) a $15,600 contribution by Milton Marketing to Mr. Milton's
    pension plan, and (ii) an aggregate of $10,952 for automobile expenses.
 
(6) Represents a cash distribution by one of the companies comprising Milton.
 
COMPENSATION COMMITTEE INTERLOCKS AND INSIDER PARTICIPATION
 
     Compensation policies and decisions, including those relating to salary,
bonuses and benefits of executive officers, have been set or made by Mr.
Girgenti, with respect to GHB&M, and Mr. Milton, with respect to Milton, since
the formation of such companies. Upon consummation of the Offering, the Board of
Directors of the Company will establish a Compensation Committee which will,
among other things, recommend to the Board of Directors the compensation to be
paid to the Company's officers. See '--Committees of the Board.'
 
                                       35
EMPLOYMENT AGREEMENTS
 
     The Company will enter into a three-year employment agreement with each of
Messrs. Girgenti, Milton, Butler, Ehrenthal, Hughes and Garnham (the 'Executive
Employment Agreements'), which will provide that Messrs. Girgenti, Milton,
Butler, Ehrenthal, Hughes and Garnham (the 'Executives') will serve as the
Company's Chairman of the Board and Chief Executive Officer, Vice Chairman of
the Board and President, President--Global Communications Services,
President--U.S. Communications Services, Chief Creative Officer and Managing
Director--Headcount, respectively, at an annual salary of $360,000, $325,000,
$300,000, $300,000, $225,000 and $175,000, respectively, subject to annual
review and increase at the discretion of the Board of Directors of the Company.
Each Executive Employment Agreement is automatically renewable after the initial
three-year term for successive one year periods unless either the Company or the
Executive notifies the other at least 30 days prior to the expiration of any
term of its or his desire to terminate the agreement. Each Executive Employment
Agreement will also contain a confidentiality provision as well as a
noncompetition provision which will prohibit the Executive from competing with

the Company during the term of the applicable agreement and for a two year
period after the expiration of such term. Under Mr. Girgenti's Executive
Employment Agreement, in the event that the Company terminates Mr. Girgenti
without cause (as defined in the agreement) prior to the expiration of the
agreement, the Company will be obligated to pay Mr. Girgenti severance in an
amount equal to twice his then current base salary.
 
     Furthermore, each Executive Employment Agreement (other than Mr. Hughes'
agreement) will provide that Messrs. Girgenti, Milton, Butler, Ehrenthal and
Garnham will be entitled to a bonus based on achieving or exceeding certain
profits and revenue performance goals set by the Company during the term of
their respective employment agreement. Mr. Ehrenthal's agreement will also
provide that he will be entitled to a two year consulting arrangement, at the
end of his employment term, for $120,000 per annum.
 
     In August 1997, the Company entered into a three-year employment agreement
with Stuart Diamond (the 'Diamond Employment Agreement'), which provides that
Mr. Diamond will serve as the Company's Executive Vice President and Chief
Financial Officer at an annual base salary of $175,000, subject to annual review
and increase at the discretion of the Board of Directors of the Company. The
Diamond Employment Agreement also provides that Mr. Diamond will receive a
minimum bonus of $30,000 for the year ending December 31, 1997 and may be
entitled to additional annual bonuses as determined by the Board of Directors in
its sole discretion. The Diamond Employment Agreement is automatically renewable
after the initial three-year term for successive one year periods unless either
the Company or Mr. Diamond notifies the other at least 30 days prior to the
expiration of any term of its or his desire to terminate the agreement. The
Diamond Employment Agreement contains a confidentiality provision as well as a
non-competition provision which prohibits Mr. Diamond from competing with the
Company during the term of the agreement. Under the Diamond Employment
Agreement, the Company will be obligated to pay Mr. Diamond severance in an
amount equal to (i) six months base salary, in the event that the Company
terminates Mr. Diamond without cause (as defined in the agreement) prior to or
subsequent to the expiration of the agreement, and (ii) a minimum of three
months base salary (subject to increase at the discretion of the Board of
Directors) in the event that the Company is sold or a change of control in the
Company occurs.
 
STOCK OPTION PLAN
 
     Prior to the date of this Prospectus, the Board of Directors will adopt,
and the stockholders will approve, the Company's 1997 Stock Option Plan ('Stock
Option Plan'). The Stock Option Plan will provide for the grant of (i) options
that are intended to qualify as incentive stock options ('Incentive Stock
Options') within the meaning of Section 422 of the Code to certain employees
(including officers and directors who are employees) and (ii) options not
intended to so qualify to the Company's employees, officers, directors and
consultants. The total number of shares of Common Stock for which options may be
granted under the Stock Option Plan will be 710,000. To date, no stock options
have been granted under the Stock Option Plan. On the effective date of the
Offering, the Company will grant options under the Stock Option Plan to purchase
up to an aggregate of        shares of Common Stock at an exercise price per
share equal to the initial public offering price.
 

     The Stock Option Plan will be administered by the Compensation Committee,
which, under such plan, must be comprised of two or more non-employee directors
who will determine the terms of options to be granted under such plan, including
the exercise price, the number of shares subject to the option and the terms and
conditions of exercise. No option granted under the Stock Option Plan will be
transferable by the optionee other than by will or
 
                                       36
the laws of descent and distribution and each option will be exercisable during
the lifetime of the optionee only by such optionee.
 
     The exercise price of all stock options granted under the Stock Option Plan
must be at least equal to the fair market value of such shares on the date of
grant. With respect to any participant who owns stock possessing more than 10%
of the voting rights of the Company's outstanding capital stock, the exercise
price of any Incentive Stock Option must be not less than 110% of the fair
market value on the date of grant. The term of each option granted pursuant to
the Stock Option Plan will be established by the Compensation Committee in its
sole discretion; provided, however, that the maximum term of each Incentive
Stock Option granted pursuant to the Stock Option Plan is ten years. With
respect to any Incentive Stock Option granted to a participant who owns stock
possessing more than 10% of the total combined voting power of all classes of
the Company's outstanding capital stock, the maximum term is five years. Except
as otherwise provided by the Compensation Committee at the time of grant,
options shall become exercisable ratably over five years commencing on the first
anniversary of the date of grant.
 
     The Stock Option Plan also will provide for an automatic annual option
grant for the non-employee directors. Each non-employee director will
automatically receive an option grant for 2,500 shares of Common Stock on the
effective date of the Offering and on the date of each annual meeting of
stockholders thereafter. In addition, a non-employee director who becomes a
director subsequent to the effective date of the Offering and other than on the
date of any annual meeting of stockholders will receive an option grant for
2,500 shares of Common Stock on the date he or she becomes a director. Each
grant will be at an exercise price per share equal to the market price of the
Common Stock on the grant date, will become fully exercisable on the first
anniversary of the date of grant, and will have a term of ten years measured
from the grant date, subject to earlier termination if an optionee's service as
a Board member is terminated for cause.
 
COMPENSATION OF DIRECTORS
 
     Each non-employee member of the Board of Directors will receive an annual
fee of $2,000 plus reimbursement of expenses incurred in attending meetings.
Additionally, each non-employee member of the Board of Directors will
automatically receive option grants, as provided in the Stock Option Plan. See
'Stock Option Plan.'
 
KEY PERSON LIFE INSURANCE
 
     The Company intends to obtain $4 million and $2 million term life insurance
policies covering Mr. Girgenti and Mr. Milton, respectively. The Company will be

the sole beneficiary of such policies.
 
                                       37
CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS
 
     Prior to the consummation of the Offering, Healthworld will enter into the
Consolidation Agreements with the stockholders of GHB&M and Milton pursuant to
which, on the effective date of the Offering, Healthworld will acquire all of
the issued and outstanding stock of each of GHB&M and Milton from the
stockholders of GHB&M and Milton in exchange for an aggregate of 5,000,000
shares of Common Stock of the Company, at which time GHB&M and Milton will
become wholly-owned subsidiaries of Healthworld. See 'The Consolidation.'
 
     Immediately prior to the consummation of the Consolidation, GHB&M will make
the S Corporation Distributions to its stockholders of approximately $3.5
million in the aggregate from existing cash balances for the payment by such
stockholders of taxes due on S Corporation earnings. See 'The Consolidations.'
 
     GHB&M has incurred indebtedness which is personally guaranteed by its
stockholders or by entities controlled by its stockholders. In particular, the
payment of all obligations under the GHB&M Credit Facility is guaranteed jointly
and severally by Messrs. Girgenti, Hughes, Butler and Ehrenthal, individually,
and by certain of the companies comprising GHB&M. At June 30, 1997, the
aggregate principal amount of indebtedness outstanding under the GHB&M Credit
Facility was $175,000. In addition, Mr. Milton has personally guaranteed
Milton's obligations under its lease for office space located in Windsor,
Berkshire. The lease expires in June 2004, and the current annual base rent
under the lease is approximately $127,000. Pursuant to the terms of the
Consolidation Agreements, the Company will use commercially reasonable efforts
to have such stockholders' personal guarantees on the balance of the
indebtedness and the obligations under the lease released within 120 days after
the consummation of the Consolidation and, in the event that the guarantee on
the indebtedness cannot be released, to repay the balance of such indebtedness
or to assume the obligations under the lease, as the case may be.
 
     In 1991, each of the companies comprising GHB&M and each of their
stockholders entered into certain stockholders' agreements. Under the
Consolidation Agreements, GHB&M and its stockholders will agree to terminate
such agreements, concurrent with the consummation of the Consolidation.
 
     Todtman, Young, Nachamie, Hendler & Spizz, P.C., of which Alex Spizz, a
Director Nominee, is a partner, represents GHB&M, Healthworld B.V. and the
Company in connection with the Consolidation and other corporate matters.
 
                                       38
PRINCIPAL STOCKHOLDERS
 
     The following table sets forth certain information regarding the beneficial
ownership of shares of Common Stock as of the date of this Prospectus, after
giving effect to the Consolidation, for (i) each director and Director Nominee;
(ii) each person known by the Company to be the beneficial owner of more than 5%
of the outstanding shares of Common Stock; (iii) each executive officer of the

Company and (iv) all directors, Director Nominees and executive officers of the
Company as a group. Each stockholder has sole voting and investment power with
respect to the shares set forth opposite such stockholder's name. All persons
listed below have an address c/o the Company's principal executive offices in
New York.
PERCENTAGE BENEFICIALLY OWNED
                                                                                     ------------------------------------
NAME                                                           NUMBER OF SHARES      BEFORE OFFERING     AFTER OFFERING
-----------------------------------------------------------   -------------------    ---------------    -----------------
Steven Girgenti............................................        2,195,925               43.9%               30.9%
William Leslie Milton......................................        1,297,330               25.9%               18.3%
Stuart Diamond.............................................         --                       --                  --
William B. Butler..........................................          485,070                9.7%                6.8%
Herbert Ehrenthal..........................................          596,505               11.9%                8.0%
Francis Hughes.............................................          172,500                3.5%                2.4%
Michael Garnham............................................          188,571                3.8%                2.7%
Peter Knight...............................................         --                       --                  --
Colin Lloyd................................................         --                       --                  --
Jonah Shacknai.............................................         --                       --                  --
Alex Spizz.................................................         --                       --                  --
All directors, Director Nominees and executive officers as
  a group (11 persons).....................................        4,935,901               98.7%               69.5%
39
DESCRIPTION OF CAPITAL STOCK
 
     The following summary description of the Company's capital stock and
certain provisions of the Company's Certificate of Incorporation and Bylaws does
not purport to be complete and is qualified in its entirety by reference to the
Company's Certificate of Incorporation and Bylaws, copies of which have been
filed with the Securities and Exchange Commission (the 'Commission') as exhibits
to the Company's registration statement on Form S-1 (the 'Registration
Statement') of which this Prospectus forms a part.
 
GENERAL
 
     The Company's authorized capital stock consists of 20,000,000 shares of
Common Stock, par value $.01 per share, and 1,000,000 shares of preferred stock,
par value $.01 per share (the 'Preferred Stock'). After giving effect to the
Consolidation, but prior to the consummation of the Offering, the Company will
have outstanding 5,000,000 shares of Common Stock and no shares of Preferred
Stock, and will have eight holders of record of Common Stock. Upon completion of
the Offering, the Company will have outstanding 7,100,000 shares of Common Stock
(7,415,000 shares if the Underwriters' over-allotment option is exercised in
full) and no shares of Preferred Stock.
 
COMMON STOCK
 

     Holders of Common Stock are entitled to one vote for each share held of
record on each matter submitted to a vote of stockholders. Subject to the prior
rights of any series of Preferred Stock which may from time to time be
outstanding, holders of Common Stock are entitled to receive ratably, dividends
when, as and if declared by the Board of Directors out of funds legally
available therefor and, upon the liquidation, dissolution, or winding up of the
Company, are entitled to share ratably in all assets remaining after payment of
liabilities and payment of accrued dividends and liquidation preferences on the
Preferred Stock, if any. Holders of Common Stock have no preemptive rights and
have no rights to convert their Common Stock into any other securities. The
outstanding Common Stock is, and the shares of Common Stock to be issued
pursuant to the Consolidation and the Offering will be, upon payment therefor,
fully paid and nonassessable.
 
PREFERRED STOCK
 
     The Preferred Stock may be issued from time-to-time by the Board of
Directors in one or more series. Subject to the provisions of the Company's
Certificate of Incorporation and limitations prescribed by law, the Board of
Directors is expressly authorized to adopt resolutions to issue shares, to fix
the number of shares and to change the number of shares constituting any series
and to provide for or change the voting powers, designations, preferences and
relative, participating, optional or other special rights, qualifications,
limitations or restrictions thereof, including dividend rights (including
whether dividends are cumulative), dividend rates, terms of redemption
(including sinking fund provisions), redemption prices, conversion rights and
liquidation preferences of the shares constituting any series of the Preferred
Stock, in each case without any further action or vote by the stockholders. The
Company has no current plans to issue any shares of Preferred Stock.
 
     The issuance of Preferred Stock, while providing desired flexibility in
connection with possible acquisitions and other corporate purposes, could have
the effect of rendering more difficult or discouraging an attempt to obtain
control of the Company by means of a tender offer, proxy contest, merger or
otherwise, thereby protecting the continuity of the Company's management. The
issuance of shares of the Preferred Stock pursuant to the Board of Directors'
authority described above may adversely affect the rights of the holders of
Common Stock. For example, Preferred Stock issued by the Company may rank prior
to the Common Stock as to dividend rights, liquidation preference or both, may
have full or limited voting rights and may be convertible into shares of Common
Stock. Accordingly, the issuance of shares of Preferred Stock may discourage
bids for the Common Stock or may otherwise adversely affect the market price of
the Common Stock.
 
LIMITATION OF LIABILITY
 
     The Company's Certificate of Incorporation and By-laws include provisions
which eliminate the personal liability of the Company's directors and officers
for monetary damages resulting from breaches of their fiduciary duty of care
(provided that such provision does not eliminate liability for breaches of the
duty of loyalty, acts or omissions not in good faith or which involve
intentional misconduct or a knowing violation of law, violations of Section 174
of the Delaware General Corporation Law, or for any transaction from which the
director derived an

 
                                       40
improper personal benefit). These provisions do not limit or eliminate the right
of the Company or any stockholder to seek non-monetary relief such as an
injunction or rescission in the event of a breach of a director's duty of care.
The Certificate of Incorporation also provides that the Company shall indemnify
its directors and officers to the fullest extent permitted by Section 145 of the
Delaware General Corporation Law, including circumstances in which
indemnification is otherwise discretionary. The Company believes that these
provisions are necessary to attract and retain qualified directors and officers.
It is the position of the Commission that indemnification for liabilities under
the Securities Act is against public policy as expressed in the Securities Act
and is, therefore, unenforceable.
 
DELAWARE ANTI-TAKEOVER LAW
 
     Under Section 203 of the Delaware General Corporation Law (the 'Delaware
anti-takeover law'), certain 'business combinations' are prohibited between a
Delaware corporation, the stock of which is generally publicly traded or held of
record by more than 2,000 stockholders, and an 'interested stockholder' of such
corporation for a three-year period following the date that such stockholder
became an interested stockholder, unless (i) the corporation has elected in its
certificate of incorporation not to be governed by the Delaware anti-takeover
law (the Company has not made such an election), (ii) the business combination
is approved by the board of directors of the corporation before the other party
to the business combination became an interested stockholder, (iii) upon
consummation of the transaction which resulted in the stockholder becoming an
interested stockholder, the interested stockholder owned at least 85% of the
voting stock of the corporation outstanding at the commencement of the
transaction (excluding voting stock owned by directors who are also officers or
held in employee benefit plans in which the employees do not have a confidential
right to tender or vote stock held by the plan), or (iv) the business
combination was approved by the board of directors of the corporation and
ratified by 66 2/3% of the voting stock which the interested stockholder did not
own. The three-year prohibition also does not apply to certain business
combinations proposed by an interested stockholder following the announcement or
notification of certain extraordinary transactions involving the corporation and
a person who had not been an interested stockholder during the previous three
years or who became an interested stockholder with the approval of a majority of
the corporation's directors. The term 'business combination' is defined
generally to include mergers or consolidations between a Delaware corporation
and an interested stockholder, transactions with an interested stockholder
involving the assets or stock of the corporation or its majority-owned
subsidiaries, and transactions which increase an interested stockholder's
percentage ownership of stock. The term 'interested stockholder' is defined
generally as those stockholders who become beneficial owners of 15% or more of a
Delaware corporation's voting stock.
 
     These provisions could delay or frustrate the removal of incumbent
directors or a change in control of the Company. The provisions also could
discourage, impede, or prevent a merger, tender offer or proxy contest, even if
such event would be favorable to the interests of stockholders.
 

TRANSFER AGENT
 
     American Stock Transfer & Trust Company is the transfer agent and registrar
for the Common Stock.
 
                                       41
SHARES ELIGIBLE FOR FUTURE SALE
 
     Upon consummation of the Consolidation and completion of the Offering, the
Company will have outstanding 7,100,000 shares of Common Stock. All of the
2,100,000 shares of Common Stock offered hereby (plus any additional shares sold
upon exercise of the Underwriters' over-allotment option) will be freely
tradeable without restriction or further registration under the Securities Act,
except for any shares purchased by any person who is or thereby becomes an
'affiliate' of the Company, which shares will be subject to the resale
limitations contained in Rule 144 promulgated under the Securities Act as
described below. The remaining 5,000,000 shares of Common Stock which will be
issued to the stockholders of GHB&M and Milton in the Consolidation, will be
'restricted securities' within the meaning of Rule 144 under the Securities Act
and, in general, if held for at least one year, will be eligible for sale in the
public market in reliance upon and subject to the limitations of Rule 144.
 
     In general, under Rule 144 as currently in effect, a person (or persons
whose shares are aggregated), including a person who may be deemed to be an
'affiliate' of the Company as that term is defined under the Securities Act, is
entitled to sell, within any three month period, the number of shares
beneficially owned for at least one year that does not exceed the greater of (i)
one percent of the number of the then outstanding shares of Common Stock; or
(ii) the average weekly trading volume of the Common Stock during the four
calendar weeks preceding the date on which notice of the proposed sale is sent
to the Commission. Sales under Rule 144 are also subject to certain requirements
as to the manner of sale, notice and the availability of current public
information about the Company. Furthermore, a person who is deemed not to have
been an affiliate of the Company during the 90 days preceding a sale by such
person and who has beneficially owned such shares for at least two years is
entitled to sell such shares without regard to the volume, manner of sale or
notice requirement.
 
     The Company and its officers and directors and the stockholders of GHB&M
and Milton will enter into Lock-up Agreements ('Lock-up Agreements') under which
they will agree not to offer, sell or otherwise dispose of any of their shares
of Common Stock or other securities of the Company for a period of 180 days,
commencing upon the date of this Prospectus, without the prior written consent
of Unterberg Harris, other than sales or issuances by the Company pursuant to
the exercise of the Underwriters' over-allotment option or pursuant to the grant
of stock options under the Company's Stock Option Plan.
 
     The stockholders of GHB&M and Milton will, pursuant to the Consolidation
Agreements, be granted the right by the Company, commencing one year from the
effective date of the Offering, to require the Company, subject to certain
exceptions, to include their shares (up to 5,000,000 in the aggregate) in any
and all offerings in which the Company proposes to register shares of Common
Stock for its own account or for the account of others under the Securities Act,

subject to the right of any managing underwriter of any such offering to exclude
some or all of the shares for marketing reasons.
 
     Prior to the Offering, no public market for the Company's securities has
existed. Following the Offering, no predictions can be made as to the effect, if
any, of future public sales of restricted shares or the availability of
restricted shares for sale in the public market. Nevertheless, the sale or
availability for sale of substantial amounts of Common Stock in the public
market could adversely affect prevailing market prices and the ability of the
Company to raise equity capital in the future.
 
                                       42
UNDERWRITING
 
     Subject to the terms and conditions set forth in an underwriting agreement
(the 'Underwriting Agreement'), the Company has agreed to sell to each of the
Underwriters named below, and each of the Underwriters, for whom Unterberg
Harris and Pennsylvania Merchant Group Ltd are acting as Representatives, have
severally agreed to purchase, the respective number of shares of Common Stock
set forth opposite its name below:
NUMBER
UNDERWRITER                                                                                   OF SHARES
-------------------------------------------------------------------------------------------   ---------
Unterberg Harris...........................................................................
Pennsylvania Merchant Group Ltd............................................................
 
                                                                                              ---------
     Total.................................................................................   2,100,000
                                                                                              ---------
                                                                                              ---------
In the Underwriting Agreement, the several Underwriters have agreed,
subject to the terms and conditions set forth therein, to purchase all of the
shares of Common Stock offered hereby if any such shares are purchased. In the
event of a default by an Underwriter, the Underwriting Agreement provides that,
in certain circumstances, such commitments of the non-defaulting Underwriters
may be increased or the Underwriting Agreement may be terminated.
 
     The Representatives have advised the Company that the Underwriters propose
initially to offer the shares of Common Stock offered hereby to the public at
the public offering price per share set forth on the cover page of this
Prospectus and to certain dealers at such price less a concession not in excess
of $        per share. The Underwriters may allow, and such dealers may reallow,
a discount not in excess of $        per share on sales to certain other
dealers. After the public offering, the offering price, discount and reallowance
may be changed.
 
     The Company has granted the Underwriters an option, which may be exercised

within 30 days after the date of this Prospectus, to purchase up to an
additional 315,000 shares of Common Stock to cover over-allotments, if any, at
the initial public offering price, less the underwriting discount. To the extent
that the Underwriters exercise the option, each of the Underwriters will have a
firm commitment, subject to certain conditions, to purchase approximately the
same percentage of shares that the number of shares of Common Stock to be
purchased by it shown on the foregoing table bears to the total number of shares
initially offered hereby.
 
     The Company has agreed to indemnify the Underwriters against certain civil
liabilities, including liabilities under the Securities Act, or to contribute to
payments the Underwriters may be required to make in respect thereof.
 
     The Company has agreed to pay the Representatives a non-accountable expense
allowance equal to 1% of the aggregate offering price of the shares of Common
Stock offered hereby (including any shares of Common Stock purchased pursuant to
the exercise of the Underwriters' over-allotment option).
 
     In connection with the Offering, the Underwriters may purchase and sell the
Common Stock in the open market. These transactions may include (i)
over-allotment transactions, (ii) stabilizing transactions, consisting of
certain bids or purchases for the purpose of preventing or restraining a decline
in the market price of the Common Stock, and (iii) purchases to cover syndicate
short positions created in connection with the Offering. The Underwriters also
may impose a penalty bid, whereby selling concessions allowed to syndicate
members or other broker-dealers in respect of the Common Stock sold in the
Offering for their account may be reclaimed by the
 
                                       43
syndicate if such shares of Common Stock are repurchased by the syndicate in
stabilizing or covering transactions. These activities may stabilize, maintain
or otherwise affect the market price of the Common Stock which may be higher
than the price that might otherwise prevail in the open market. These
transactions may be effected on The Nasdaq National Market or otherwise, and
these activities, if commenced, may be discontinued at any time.
 
     The Underwriters have informed the Company that they do not intend to
confirm sales to any accounts over which they exercise discretionary authority.
 
     The Company has applied for quotation of the Common Stock on The Nasdaq
National Market under the symbol 'HWLD.'
 
     The Company and its officers and directors and the stockholders of GHB&M
and Milton will enter into Lock-Up Agreements under which they will agree not to
offer, sell or otherwise dispose of any of their shares of Common Stock or other
securities of the Company for a period of 180 days after the date of this
Prospectus without the prior written consent of Unterberg Harris, other than
sales or issuances by the Company pursuant to the exercise of the Underwriters'
over-allotment option or pursuant to the grant of stock options under the
Company's Stock Option Plan.
 
     Prior to the Offering, there has been no public market for the Common
Stock. The initial public offering price of the Common Stock offered hereby will

be arbitrarily determined by negotiation between the Company and the
Representatives and will not necessarily be related to the Company's asset
value, net worth or other established criteria of value. In determining the
initial public offering price, the Representatives and the Company will
consider, among other things, market prices of similar securities of comparable
publicly traded companies, the financial conditions and operating information of
companies engaged in activities similar to those of the Company, the financial
condition and prospects of the Company and the general condition of the
securities market.
 
                                 LEGAL MATTERS
 
     The validity of the shares of Common Stock offered hereby will be passed
upon for the Company by Rosenman & Colin LLP, New York, New York. Certain legal
matters in connection with the sale of the shares offered hereby will be passed
upon for the Underwriters by Akin, Gump, Strauss, Hauer & Feld, L.L.P., New
York, New York.
 
                                    EXPERTS
 
     The combined financial statements of GHB&M and the consolidated financial
statements of Milton included elsewhere in this Prospectus have been audited by
Arthur Andersen LLP, independent public accountants, as indicated in their
reports with respect thereto, and are included herein in reliance upon the
authority of said firm as experts in accounting and auditing in giving said
reports.
 
                           FORWARD LOOKING STATEMENTS
 
     This Prospectus and the Registration Statement, of which this Prospectus is
a part, contain various forward-looking statements and information that are
based on management's beliefs as well as assumptions made by and information
currently available to management for the Company. Although the Company believes
that the expectations reflected in such forward-looking statements are
reasonable, no assurance can be given that such expectations will prove to have
been correct. Such statements are subject to certain risks, uncertainties and
assumptions. Should one or more of these risks or uncertainties materialize, or
should underlying assumptions prove incorrect, actual results may vary
materially from those expected. Among the key factors that may have a direct
bearing on the Company's operating results are fluctuations in the economy,
successful integration of future acquisitions and the impact of competition.
 
                                       44
ADDITIONAL INFORMATION
 
     The Company is not subject to the reporting requirements of the Securities
Exchange Act of 1934, as amended (the 'Exchange Act'). The Company has filed
with the Commission a Registration Statement, together with exhibits thereto,
relating to the shares of Common Stock offered hereby. This Prospectus, which
constitutes a part of the Registration Statement, omits certain of the
information set forth in the Registration Statement. For further information
with respect to the Company and to the shares of Common Stock offered hereby,
reference is made to such Registration Statement. Statements contained in this

Prospectus as to the contents of any contract or other documents referred to are
not necessarily complete, and in each instance, reference is made to the copy of
such contract or other document filed as an exhibit to the Registration
Statement, each such statement being qualified in all respects by such
reference. The Registration Statement and exhibits may be inspected and copied
at the public reference section at the Commission's principal office, 450 5th
Street, N.W., Judiciary Plaza, Washington, D.C. 20549, and at the Commission's
Regional Offices located at the Northwestern Atrium Center, Suite 1400, 500 West
Madison Street, Chicago, Illinois 60661-2511, and 7 World Trade Center, 13th
Floor, New York, New York 10048. Copies may be obtained from the Commission's
principal office upon payment of the fees prescribed by the Commission. Copies
of such materials can be obtained from the Commission at Judiciary Plaza, 450
Fifth Street, N.W., Washington, D.C. 20545, at prescribed rates. In addition,
the Commission maintains a Website on the Internet that contains reports, proxy
and information statements and other information regarding registrants that file
electronically with the Commission. The address of the Commission's Website is
http://www.sec.gov.
 
     Following the Offering, the Company will be subject to the reporting and
other requirements of the Exchange Act and intends to furnish to its
stockholders annual reports containing audited financial statements and
quarterly reports containing unaudited consolidated summary financial
information for each of the first three quarters of each fiscal year.
 
                                       45
INDEX TO FINANCIAL STATEMENTS
PAGE
                                                                                                              ----
HEALTHWORLD CORPORATION PRO FORMA COMBINING
Introduction to Unaudited Pro Forma Combining Financial Statements.........................................    F-2
Pro Forma Combining Balance Sheets (unaudited).............................................................    F-3
Pro Forma Combining Statements of Income (unaudited).......................................................    F-6
Notes to Unaudited Pro Forma Combining Financial Statements................................................   F-11
GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES
Report of Independent Public Accountants...................................................................   F-12
Combined Balance Sheets....................................................................................   F-13
Combined Statements of Income..............................................................................   F-14
Combined Statements of Stockholders' Equity................................................................   F-15
Combined Statements of Cash Flows..........................................................................   F-16
Notes to Combined Financial Statements.....................................................................   F-17
MILTON MARKETING GROUP LIMITED AND SUBSIDIARIES
Report of Independent Public Accountants...................................................................   F-22
Consolidated Balance Sheets................................................................................   F-23
Consolidated Statements of Income..........................................................................   F-24
Consolidated Statements of Stockholders' Equity............................................................   F-25
Consolidated Statements of Cash Flows......................................................................   F-26
Notes to Consolidated Financial Statements.................................................................   F-27
F-1
HEALTHWORLD CORPORATION
               UNAUDITED PRO FORMA COMBINING FINANCIAL STATEMENTS
                             BASIS OF PRESENTATION
 
     The following unaudited pro forma combining financial statements give
effect to the contributions of the outstanding capital stock of Girgenti,
Hughes, Butler and McDowell, Inc. and its affiliated entities ('GHB&M') and
Milton Marketing Group Limited and its subsidiaries ('Milton') to Healthworld
Corporation (the 'Company') in exchange for an aggregate of 5,000,000 shares of
common stock of the Company (collectively, the 'Consolidation'). The
Consolidation will occur on the effective date of the Offering made by this
Prospectus and will be accounted for using the pooling of interests method of
accounting.
 
     The unaudited pro forma combining balance sheets give effect to the
Consolidation, among other events, as if each event had occurred on the date of
each respective balance sheet. The unaudited pro forma combining statements of
income give effect to the Consolidation, among other events, as if each event
had occurred at the beginning of each period presented.
 
     The pro forma adjustments are based on preliminary estimates, available
information and certain assumptions and may be revised as additional information
becomes available. The pro forma financial data does not purport to represent
what the Company's financial position or results of operations would actually
have been if such transactions in fact had occurred on the dates indicated or to
project the Company's financial position or results of operations for any future
period. Since GHB&M and Milton were not under common control or management,
historical combined results may not be comparable to, or indicative of, future
performance. The unaudited pro forma combining financial statements should be
read in conjunction with the other financial statements and notes thereto
included elsewhere in this Prospectus. For a discussion of the risk factors
associated with the Company and its business, see 'Risk Factors' included
elsewhere in this Prospectus.
 
                                      F-2
HEALTHWORLD CORPORATION

                  UNAUDITED PRO FORMA COMBINING BALANCE SHEETS

                               DECEMBER 31, 1995
                                 (IN THOUSANDS)
PRO FORMA
                                                                       GHB&M     MILTON    ADJUSTMENTS    PRO FORMA
                                                                      -------    ------    - ---------    ---------
                                                                                             (NOTE 2)
ASSETS
Current assets:
  Cash and cash equivalents........................................   $   627    $  511    $     --       $ 1,138
  Accounts receivable..............................................     7,854     1,058          --         8,912
  Unbilled production charges......................................     3,060        49          --         3,109
  Other current assets.............................................       242       147          --           389
                                                                      -------    ------     -------      --------
Total current assets...............................................    11,783     1,765          --        13,548
Furniture, equipment and leasehold improvements, net...............     1,136       634          --         1,770
Goodwill, net......................................................        --       994       2,015         3,009
Other assets.......................................................       368         8          --           376
                                                                      -------    ------     -------      --------
                                                                      $13,287    $3,401     $ 2,015       $18,703
                                                                      -------    ------     -------       -------
                                                                      -------    ------     -------       -------
 
               LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:
  Line of credit...................................................   $   600    $   --      $    --      $   600
  Bank loans and overdrafts........................................        --        24           --           24
  Current portion of long-term debt................................        82       107           --          189
  Current portion of capitalized lease obligation..................        --        74           --           74
  Accounts payable.................................................     1,361       340           --        1,701
  Accrued expenses.................................................       110       936           --        1,046
  Advance billings.................................................     5,569       441           --        6,010
                                                                      -------    ------      -------       -------
Total current liabilities..........................................     7,722     1,922           --         9,644
Long-term debt.....................................................        --       882           --           882
Capitalized lease obligation.......................................        --        78           --            78
Minority interests.................................................        --        89          (89)           --
Deferred rent......................................................       642        --           --           642
Deferred income taxes..............................................       118        --           --           118
                                                                      -------    ------      -------       -------
Total liabilities..................................................     8,482     2,971          (89)       11,364
                                                                      -------    ------      -------       -------
Stockholders' equity:
  Common stock.....................................................       289        --         (239)           50
  Additional paid-in capital.......................................        --        13        2,343         2,356
  Retained earnings................................................     4,516       423           --         4,939
  Cumulative foreign currency translation adjustments..............        --        (6)          --            (6)
                                                                      -------    ------      -------       -------
Total stockholders' equity.........................................     4,805       430        2,104         7,339
                                                                      -------    ------      -------       -------
                                                                      $13,287    $3,401      $ 2,015       $18,703
                                                                      -------    ------      -------       -------
                                                                      -------    ------      -------       -------
The accompanying notes are an integral part of these unaudited pro forma
                        combining financial statements.

                                      F-3
HEALTHWORLD CORPORATION

                  UNAUDITED PRO FORMA COMBINING BALANCE SHEETS

                               DECEMBER 31, 1996
                                 (IN THOUSANDS)
PRO FORMA
                                                                      GHB&M     MILTON    ADJUSTMENTS     PRO FORMA
                                                                      -------    ------   -----------     ---------
                                                                                            (NOTE 2)
ASSETS
Current assets:
  Cash and cash equivalents........................................   $ 2,214    $   --      $    --       $ 2,214
  Accounts receivable..............................................     8,539     3,266           --        11,805
  Unbilled production charges......................................     1,477        87           --         1,564
  Other current assets.............................................       122       415           --           537
                                                                      -------    ------      -------       -------
Total current assets...............................................    12,352     3,768           --        16,120
Furniture, equipment and leasehold improvements, net...............     1,242       870           --         2,112
Goodwill, net......................................................        --     1,800        2,061         3,861
Other assets.......................................................       455        49           --           504
                                                                      -------    ------      -------       -------
                                                                      $14,049    $6,487      $ 2,061       $22,597
                                                                      -------    ------      -------       -------
                                                                      -------    ------      -------       -------
 
               LIABILITIES AND STOCKHOLDERS' EQUITY

Current liabilities:
  Bank loans and overdrafts........................................   $    --    $  406      $    --       $   406
  Current portion of long-term debt................................        98       118           --           216
  Current portion of capitalized lease obligation..................        --       125           --           125
  Accounts payable.................................................     1,327     1,144           --         2,471
  Accrued expenses.................................................       120     1,977           --         2,097
  Advance billings.................................................     5,739       534           --         6,273
                                                                      -------    ------      -------       -------
Total current liabilities..........................................     7,684     4,304           --        11,988
Long-term debt.....................................................       125       825           --           950
Capitalized lease obligation.......................................        --       128           --           128
Minority interests.................................................        --       143         (143)           --
Deferred rent......................................................       665        --           --           665
Deferred income taxes..............................................       207        --           --           207
Other liabilities..................................................        --        83           --            83

                                                                      -------    ------      -------       -------
Total liabilities..................................................     8,681     5,483         (143)       14,021
                                                                      -------    ------      -------       -------
Stockholders' equity:
  Common stock.....................................................       290        --         (240)           50
  Additional paid-in capital.......................................        --        13        2,444         2,457
  Retained earnings................................................     5,078       925           --         6,003
  Cumulative foreign currency translation adjustments..............        --        66           --            66
                                                                      -------    ------      -------       -------
Total stockholders' equity.........................................     5,368     1,004        2,204         8,576
                                                                      -------    ------      -------       -------
                                                                      $14,049    $6,487      $ 2,061       $22,597
                                                                      -------    ------    -----------     -------
                                                                      -------    ------    -----------     -------
The accompanying notes are an integral part of these unaudited pro forma
                        combining financial statements.

                                      F-4
HEALTHWORLD CORPORATION

                  UNAUDITED PRO FORMA COMBINING BALANCE SHEETS

                                 JUNE 30, 1997
                                 (IN THOUSANDS)
PRO FORMA 
                                                                       GHB&M     MILTON   ADJUSTMENTS    PRO FORMA
                                                                      -------    ------   -----------    ---------
                                                                                           (NOTE 2)
ASSETS
Current assets:
  Cash and cash equivalents........................................   $ 2,049    $   19      $(1,000)      $ 1,068
  Accounts receivable..............................................     6,477     3,510       (2,500)        7,487
  Unbilled production charges......................................     3,307       273           --         3,580
  Other current assets.............................................        71       581           --           652
                                                                      -------    ------      -------       -------
Total current assets...............................................    11,904     4,383       (3,500)       12,787
Furniture, equipment and leasehold improvements, net...............     1,203       948           --         2,151
Goodwill, net......................................................        --     1,707        1,936         3,643
Other assets.......................................................     1,073       262           --         1,335
                                                                      -------    ------      -------       -------
                                                                      $14,180    $7,300      $(1,564)      $19,916
                                                                      -------    ------      -------       -------
                                                                      -------    ------      -------       -------
 
               LIABILITIES AND STOCKHOLDERS' EQUITY

Current liabilities:
  Line of credit...................................................   $    --    $   --      $    --       $    --
  Bank loans and overdrafts........................................        --     1,211           --         1,211
  Current portion of long-term debt................................        78       595           --           673
  Current portion of capitalized lease obligation..................        --        69           --            69
  Accounts payable.................................................     1,076     1,538           --         2,614
  Accrued expenses.................................................       154     1,418           --         1,572
  Advance billings.................................................     5,916       684           --         6,600
                                                                      -------    ------      -------       -------
Total current liabilities..........................................     7,224     5,515           --        12,739
Long-term debt.....................................................        98       291           --           389
Capitalized lease obligation.......................................        --       193           --           193
Minority interests.................................................        --       268         (268)           --
Deferred rent......................................................       715        --           --           715
Deferred income taxes..............................................       266        --           --           266
Other liabilities..................................................        --        57           --            57
                                                                      -------    ------      -------       -------
Total liabilities..................................................     8,303     6,324         (268)       14,359
                                                                      -------    ------      -------       -------
Stockholders' Equity:
  Common stock.....................................................       290        --         (240)           50
  Additional paid-in capital.......................................        --        13        4,568         4,581
  Retained earnings................................................     5,587       914       (5,624)          877
  Cumulative foreign currency translation adjustments..............        --        49           --            49
                                                                      -------    ------      -------       -------
Total stockholders' equity.........................................     5,877       976       (1,296)        5,557
                                                                      -------    ------      -------       -------
                                                                      $14,180    $7,300      $(1,564)      $19,916
                                                                      -------    ------      -------       -------
                                                                      -------    ------      -------       -------
The accompanying notes are an integral part of these unaudited pro forma
                        combining financial statements.

                                      F-5
HEALTHWORLD CORPORATION

               UNAUDITED PRO FORMA COMBINING STATEMENTS OF INCOME

                      FOR THE YEAR ENDED DECEMBER 31, 1994
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
PRO FORMA
                                                                       GHB&M     MILTON    ADJUSTMENTS    PRO FORMA 
                                                                      -------    ------    -----------    ---------
                                                                                             (NOTE 3)
Revenues...........................................................   $10,415    $2,666       $  --        $13,081

                                                                      -------    ------       -----        -------
Operating expenses:
     Salaries and related costs....................................     6,416     1,474          --          7,890
     Other operating expenses......................................     2,911       802          14          3,727
                                                                      -------    ------       -----        -------
                                                                        9,327     2,276          14         11,617
Income from operations.............................................     1,088       390         (14)         1,464
Interest expense, net..............................................         2        12          --             14
                                                                      -------    ------       -----        -------
Income before provision for income taxes and minority interests....     1,086       378         (14)         1,450
Provision for income taxes.........................................        19       117         477            613
Minority interests in net earnings of subsidiaries.................        --        39         (39)            --
                                                                      -------    ------       ------       -------
Net income.........................................................   $ 1,067    $  222       $(452)       $   837
                                                                      -------    ------       ------       -------
                                                                      -------    ------       ------       -------
Earnings per share.................................................                                        $  0.17
                                                                                                           -------
                                                                                                           -------
Shares used in computing earnings per share........................                                          5,000
                                                                                                           -------
                                                                                                           -------
The accompanying notes are an integral part of these unaudited pro forma
                        combining financial statements.

                                      F-6
HEALTHWORLD CORPORATION

               UNAUDITED PRO FORMA COMBINING STATEMENTS OF INCOME

                      FOR THE YEAR ENDED DECEMBER 31, 1995
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
PRO FORMA
                                                                       GHB&M     MILTON    ADJUSTMENTS    PRO FORMA 
                                                                      -------    ------    -----------    ---------
                                                                                             (NOTE 3)
Revenues...........................................................   $12,368    $4,399       $  --        $16,767
                                                                      -------    ------       -----        -------
Operating expenses:
     Salaries and related costs....................................     6,891     2,531          --          9,422
     Other operating expenses......................................     3,550     1,310          44          4,904
                                                                      -------    ------       -----        -------
                                                                       10,441     3,841          44         14,326
Income from operations.............................................     1,927       558         (44)         2,441
Interest expense, net..............................................       (13)       15          --              2

                                                                      -------    ------       -----        -------
Income before provision for income taxes and minority interests....     1,940       543         (44)         2,439
Provision for income taxes.........................................       124       159         755          1,038
Minority interests in net earnings of subsidiaries.................        --        68         (68)            --
                                                                      -------    ------       -----        -------
Net income.........................................................   $ 1,816    $  316       $(731)       $ 1,401
                                                                      -------    ------       -----        -------
                                                                      -------    ------       -----        -------
Earnings per share.................................................                                        $  0.28
                                                                                                           -------
                                                                                                           -------
Shares used in computing earnings per share........................                                          5,000
                                                                                                           -------
                                                                                                           -------
The accompanying notes are an integral part of these unaudited pro forma
                        combining financial statements.

                                      F-7
HEALTHWORLD CORPORATION

               UNAUDITED PRO FORMA COMBINING STATEMENTS OF INCOME

                      FOR THE YEAR ENDED DECEMBER 31, 1996
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
PRO FORMA
                                                                       GHB&M     MILTON    ADJUSTMENTS    PRO FORMA
                                                                      -------    ------    -----------    ---------
                                                                                             (NOTE 3)
Revenues...........................................................   $14,314    $9,895       $  --        $24,209
                                                                      -------    ------       -----        -------
Operating expenses:
     Salaries and related costs....................................     8,599     6,793          --         15,392
     Other operating expenses......................................     3,532     2,017          66          5,615
                                                                      -------    ------       -----        -------
                                                                       12,131     8,810          66         21,007
Income from operations.............................................     2,183     1,085         (66)         3,202
Interest expense, net..............................................       (24)       93          --             69
                                                                      -------    ------       -----        -------
Income before provision for income taxes and minority interests....     2,207       992         (66)         3,133
Provision for income taxes.........................................       158       366         781          1,305
Minority interests in net earnings of subsidiaries.................        --       124        (124)            --
                                                                      -------    ------       -----        -------
Net income.........................................................   $ 2,049    $  502       $(723)       $ 1,828
                                                                      -------    ------       ------       -------

                                                                      -------    ------       ------       -------
Earnings per share.................................................                                        $  0.37
                                                                                                           -------
                                                                                                           -------
Shares used in computing earnings per share........................                                          5,000
                                                                                                           -------
                                                                                                           -------
The accompanying notes are an integral part of these unaudited pro forma
                        combining financial statements.

                                      F-8
HEALTHWORLD CORPORATION

               UNAUDITED PRO FORMA COMBINING STATEMENTS OF INCOME

                     FOR THE SIX MONTHS ENDED JUNE 30, 1996
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
PRO FORMA
                                                                       GHB&M     MILTON    ADJUSTMENTS    PRO FORMA
                                                                      -------    ------    -----------    ---------
                                                                                             (NOTE 3)
Revenues...........................................................   $ 6,383    $4,939       $  --        $11,322
                                                                      -------    ------       -----        -------
Operating expenses:
     Salaries and related costs....................................     4,174     3,351          --          7,525
     Other operating expenses......................................     1,831       933          33          2,797
                                                                      -------    ------       -----        -------
                                                                        6,005     4,284          33         10,322
Income from operations.............................................       378       655         (33)         1,000
Interest expense, net..............................................       (78)       30          --            (48)
                                                                      -------    ------       -----        -------
Income before provision for income taxes and minority interests....       456       625         (33)         1,048
Provision for income taxes.........................................        33       231         161            425
Minority interests in net earnings of subsidiaries.................        --        69         (69)            --
                                                                      -------    ------       -----        -------
Net income.........................................................   $   423    $  325       $(125)       $   623
                                                                      -------    ------       -----        -------
                                                                      -------    ------       -----        -------
Earnings per share.................................................                                        $  0.12
                                                                                                           -------
                                                                                                           -------
Shares used in computing earnings per share........................                                          5,000
                                                                                                           -------
                                                                                                           -------
The accompanying notes are an integral part of these unaudited pro forma
                        combining financial statements.

                                      F-9
HEALTHWORLD CORPORATION

               UNAUDITED PRO FORMA COMBINING STATEMENTS OF INCOME

                     FOR THE SIX MONTHS ENDED JUNE 30, 1997
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
PRO FORMA
                                                                       GHB&M     MILTON    ADJUSTMENTS    PRO FORMA
                                                                      -------    ------    -----------    ---------
                                                                                             (NOTE 3)
Revenues...........................................................   $ 7,459    $7,324       $  --        $14,783
                                                                      -------    ------       -----        -------
Operating expenses:
     Salaries and related costs....................................     4,789     5,611          --         10,400
     Other operating expenses......................................     1,679     1,288          33          3,000
                                                                      -------    ------       -----        -------
                                                                        6,468     6,899          33         13,400
Income from operations.............................................       991       425         (33)         1,383
Interest expense, net..............................................       (79)       58          --            (21)
                                                                      -------    ------       -----        -------
Income before provision for income taxes and minority interests....     1,070       367         (33)         1,404
Provision for income taxes.........................................        64       135         385            584
Minority interests in net earnings of subsidiaries.................        --       126        (126)            --
                                                                      -------    ------       -----        -------
Net income.........................................................   $ 1,006    $  106       $(292)       $   820
                                                                      -------    ------       -----        -------
                                                                      -------    ------       -----        -------
Earnings per share.................................................                                        $  0.16
                                                                                                           -------
                                                                                                           -------
Shares used in computing earnings per share........................                                          5,000
                                                                                                           -------
                                                                                                           -------
The accompanying notes are an integral part of these unaudited pro forma
                        combining financial statements.

                                      F-10
HEALTHWORLD CORPORATION

          NOTES TO UNAUDITED PRO FORMA COMBINING FINANCIAL STATEMENTS

                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
1. GENERAL
 
     Healthworld Corporation (the 'Company') was incorporated in Delaware on
September 12, 1996. The Company has conducted no operations to date and will
acquire all of the outstanding common stock of Girgenti, Hughes, Butler and
McDowell, Inc. and its affiliated entities ('GHB&M') and Milton Marketing Group
Limited and its subsidiaries ('Milton') in exchange for an aggregate of 5,000
shares of common stock of the Company (the 'Consolidation') as of the effective
date of the Offering made by this Prospectus. The Consolidation will be
accounted for using the pooling of interests method of accounting.
 
     The periods included in these unaudited pro forma combining financial
statements are as follows: GHB&M--combined balance sheets as of December 31,
1995 and 1996 and June 30, 1997, and combined income statements for the years
ended December 31, 1994, 1995 and 1996, and the six months ended June 30, 1996
and 1997; and Milton--consolidated balance sheets as of November 30, 1995 and
1996 and June 30, 1997, and consolidated income statements for the years ended
November 30, 1994, 1995 and 1996, and the six months ended June 30, 1996 and
1997.
 
2. UNAUDITED PRO FORMA BALANCE SHEET ADJUSTMENTS
 
     The following pro forma adjustments have been made to the Company's pro
forma combining balance sheets to reflect:
 
     a. the Consolidation;
 
     b. an estimated $3,500 distribution to be made to the stockholders of the
        companies comprising GHB&M (other than Syberactive, Inc.) immediately
        prior to the consummation of the Consolidation from existing cash
        balances for payment by such stockholders of income taxes on 'S'
        Corporation earnings;
 
     c. an increase in additional paid-in capital of $2,124 and a corresponding
        decrease in 'S' Corporation retained earnings of GHB&M as if the 'S'
        Corporation status of the companies comprising GHB&M was terminated on
        June 30, 1997;
 
     d. the purchase of minority interests of the companies comprising Milton
        and the goodwill resulting therefrom; and
 
     e. the sale of an estimated $2,500 of accounts receivable of GHB&M to an
        unaffiliated financial institution at a negotiated discount rate prior
        to the consummation of the Consolidation. Such sale will be undertaken
        in connection with the termination of the status of each of the
        companies comprising GHB&M as 'S' Corporations, which will occur as a
        result of and upon consummation of the Consolidation.
 

3. UNAUDITED PRO FORMA STATEMENT OF INCOME ADJUSTMENTS
 
     The following pro forma adjustments have been made to the Company's pro
forma combining statements of income to reflect:
 
     a. a provision for federal and state income taxes as if each of the
        companies comprising GHB&M were treated as 'C' Corporations rather than
        'S' Corporations for such periods; and
 
     b. the purchase of minority interests of the companies comprising Milton
        and the goodwill amortization resulting therefrom.
 
                                      F-11
After the execution of definitive agreements to undertake the Consolidation
discussed in Note 9 to the combined financial statements of Girgenti, Hughes,
Butler & McDowell, Inc. and Affiliates, we expect to be in a position to render
the following audit report.
 
                                                  /s/ Arthur Andersen
                                            --------------------------------
                                                     Arthur Andersen

 
August 29, 1997

 
                    REPORT OF INDEPENDENT PUBLIC ACCOUNTANTS

 
To Girgenti, Hughes, Butler & McDowell, Inc.
and Affiliates:
 
We have audited the accompanying combined balance sheets of Girgenti, Hughes,
Butler & McDowell, Inc. (a New York corporation) and Affiliates as of December
31, 1995 and 1996, and the related combined statements of income, stockholders'
equity and cash flows for each of the three years in the period ended December
31, 1996. These financial statements are the responsibility of the Company's
management. Our responsibility is to express an opinion on these financial
statements based on our audits.
 
We conducted our audits in accordance with generally accepted auditing
standards. Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of material
misstatement. An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements. An audit also includes
assessing the accounting principles used and significant estimates made by
management, as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.
 
In our opinion, the financial statements referred to above present fairly, in
all material respects, the financial position of Girgenti, Hughes, Butler &
McDowell, Inc. and Affiliates as of December 31, 1995 and 1996, and the results
of their operations and their cash flows for each of the three years in the
period ended December 31, 1996 in conformity with generally accepted accounting
principles.
 
Melville, New York
January 24, 1997
  (except with respect to the matters
  discussed in Note 9 as to which
  the date is              , 1997)
 
                                      F-12
GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

                            COMBINED BALANCE SHEETS
                                 (IN THOUSANDS)
DECEMBER 31,
                                                                                  ------------------     JUNE 30,
                                                                                   1995       1996         1997
                                                                                  -------    -------    -----------
                                                                                                        (UNAUDITED)
ASSETS
Current assets:
  Cash and cash equivalents....................................................   $   627    $ 2,214      $ 2,049
  Accounts receivable..........................................................     7,854      8,539        6,477
  Unbilled production charges, at cost.........................................     3,060      1,477        3,307
  Other current assets.........................................................       242        122           71
                                                                                  -------    -------      -------
Total current assets...........................................................    11,783     12,352       11,904
Furniture, equipment and leasehold improvements, net...........................     1,136      1,242        1,203
Other assets...................................................................       368        455        1,073
                                                                                  -------    -------      -------
                                                                                  $13,287    $14,049      $14,180
                                                                                  -------    -------      -------
                                                                                  -------    -------      -------
                     LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:
  Line of credit...............................................................   $   600    $   400      $    --
  Current portion of long-term debt............................................        82         98           78
  Accounts payable.............................................................     1,361      1,327        1,076
  Accrued expenses.............................................................       110        120          154
  Advance production billings..................................................     5,569      5,739        5,916
                                                                                  -------    -------      -------
Total current liabilities......................................................     7,722      7,684        7,224
Commitments (Note 7)
Long-term debt.................................................................        --        125           98
Deferred rent..................................................................       642        665          715
Deferred income taxes..........................................................       118        207          266
                                                                                  -------    -------      -------
                                                                                    8,482      8,681        8,303
                                                                                  -------    -------      -------
Stockholders' equity:
  Common stock.................................................................       289        290          290
  Retained earnings............................................................     4,516      5,078        5,587
                                                                                  -------    -------      -------
Total stockholders' equity.....................................................     4,805      5,368        5,877
                                                                                  -------    -------      -------
                                                                                  $13,287    $14,049      $14,180
                                                                                  -------    -------      -------
                                                                                  -------    -------      -------
The accompanying notes to combined financial statements are an integral part of
                             these balance sheets.

                                      F-13
GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

                         COMBINED STATEMENTS OF INCOME
                                 (IN THOUSANDS)
SIX MONTHS
                                                                   YEAR ENDED DECEMBER 31,        ENDED JUNE 30,
                                                                -----------------------------    ----------------
                                                                 1994       1995       1996       1996      1997
                                                                -------    -------    -------    ------    ------
                                                                                                   (UNAUDITED)
Revenues.....................................................   $10,415    $12,368    $14,314    $6,383    $7,459
                                                                -------    -------    -------    ------    ------
Operating expenses:
  Salaries and related costs.................................     6,416      6,891      8,599     4,174     4,789
  Other operating expenses...................................     2,911      3,550      3,532     1,831     1,679
                                                                -------    -------    -------    ------    ------
                                                                  9,327     10,441     12,131     6,005     6,468
Income from operations.......................................     1,088      1,927      2,183       378       991
Interest expense, net........................................         2        (13)       (24)      (78)      (79)
                                                                -------    -------    -------    ------    ------
Income before provision for income taxes.....................     1,086      1,940      2,207       456     1,070
Provision for income taxes...................................        19        124        158        33        64
                                                                -------    -------    -------    ------    ------
Net income...................................................   $ 1,067    $ 1,816    $ 2,049    $  423    $1,006
                                                                -------    -------    -------    ------    ------
                                                                -------    -------    -------    ------    ------
The accompanying notes to combined financial statements are an integral part of
                               these statements.

                                      F-14
GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

                  COMBINED STATEMENTS OF STOCKHOLDERS' EQUITY
                                 (IN THOUSANDS)
COMMON    RETAINED
                                                                                                STOCK     EARNINGS
                                                                                                ------    --------
Balance, December 31, 1993...................................................................    $289      $2,386
  Net income.................................................................................      --       1,067
  Stockholders' distributions................................................................      --        (544)
                                                                                                ------     ------
Balance, December 31, 1994...................................................................     289       2,909
  Net income.................................................................................      --       1,816
  Stockholders' distributions................................................................      --        (209)
                                                                                                ------     ------
Balance, December 31, 1995...................................................................     289       4,516
  Net income.................................................................................      --       2,049
  Stockholders' distributions................................................................      --      (1,487)
  Issuance of common stock in new affiliate..................................................       1          --
                                                                                                ------     ------
Balance, December 31, 1996...................................................................     290       5,078
  Net income (unaudited).....................................................................      --       1,006
  Stockholders' distributions (unaudited)....................................................      --        (497)
                                                                                                ------     ------
Balance, June 30, 1997 (unaudited)...........................................................    $290      $5,587
                                                                                                ------     ------
                                                                                                ------     ------
The accompanying notes to combined financial statements are an integral part of
                               these statements.

                                      F-15
GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

                       COMBINED STATEMENTS OF CASH FLOWS
                                 (IN THOUSANDS)
SIX MONTHS
                                                                   YEAR ENDED DECEMBER 31,       ENDED JUNE 30,
                                                                   ------------------------     ----------------
                                                                    1994     1995     1996       1996      1997
                                                                   ------   ------   ------     ------    ------
                                                                                                  (UNAUDITED)
Cash flows from operating activities:
  Net income.....................................................  $1,067   $1,816   $2,049     $  423    $1,006
     Adjustments to reconcile net income to net cash provided by
     operating activities:
       Depreciation and amortization.............................     214      274      402        174       196
       Deferred rent.............................................      80      200       23         12        50
       Deferred income taxes.....................................      --       83       89         33        59

     Changes in operating assets and liabilities:
       Accounts receivable.......................................  (1,652)     336     (685)       703     2,062
       Unbilled production charges...............................     287     (719)   1,583        555    (1,830)
       Other current assets......................................      18      (88)     120       (108)       51
       Other assets..............................................      95       30      (88)       (34)     (618)
       Accounts payable..........................................    (145)     253      (35)      (798)     (251)
       Advanced production billing...............................   1,313   (1,653)     171         (1)      177
       Accrued expenses..........................................    (125)      98        9         10        34
                                                                   ------   ------   ------     ------    ------
Net cash provided by operating activities........................   1,152      630    3,638        969       936
                                                                   ------   ------   ------     ------    ------
Cash flows from investing activities:
  Capital expenditures, net......................................    (258)    (563)    (507)      (203)     (157)
                                                                   ------   ------   ------     ------    ------
Net cash (used in) investing activities..........................    (258)    (563)    (507)      (203)     (157)
                                                                   ------   ------   ------     ------    ------
Cash flows from financing activities:
  Distributions to stockholders..................................    (544)    (209)  (1,487)      (621)     (497)
  Net (repayment) proceeds from line of credit...................    (100)     200     (200)      (100)     (400)
  Issuance of long-term debt.....................................      --       --      300        300        --
  Repayment of long-term debt....................................     (97)    (105)    (158)       (86)      (47)
  Issuance of common stock in new affiliate......................      --       --        1          1        --
                                                                   ------   ------   ------     ------    ------
Net cash (used in) financing activities..........................    (741)    (114)  (1,544)      (506)     (944)
                                                                   ------   ------   ------     ------    ------
Net increase/(decrease) in cash and cash equivalents.............     153      (47)   1,587        260      (165)
Cash and cash equivalents at beginning of year...................     521      674      627        627     2,214
                                                                   ------   ------   ------     ------    ------
Cash and cash equivalents at end of year.........................  $  674   $  627   $2,214     $  887    $2,049
                                                                   ------   ------   ------     ------    ------
                                                                   ------   ------   ------     ------    ------
Supplemental disclosure of cash flow information:
  Cash paid for taxes............................................  $   17   $   45   $   64     $   45    $   64
                                                                   ------   ------   ------     ------    ------
                                                                   ------   ------   ------     ------    ------
  Cash paid for interest.........................................  $   30   $   31   $   41     $   31    $    8
                                                                   ------   ------   ------     ------    ------
                                                                   ------   ------   ------     ------    ------
The accompanying notes to combined financial statements are an integral part of
                               these statements.

                                      F-16
GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

                     NOTES TO COMBINED FINANCIAL STATEMENTS
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
1. BUSINESS
 
     Girgenti, Hughes, Butler & McDowell, Inc. and Affiliates (the 'Company') is
a combined group of six affiliated companies: Girgenti, Hughes, Butler &
McDowell, Inc. ('GHB&M'); Black Cat Graphics, Inc. ('Black Cat'); Medical
Educational Technologies, Inc. ('MET'); Brand Research Corporation ('Brand');
GHBM, Inc. and Syberactive Inc. ('Syberactive'). Each of these companies is
owned in the same manner by a stockholder group consisting of four individuals.
 
     The Company provides a broad range of integrated marketing and
communications services including advertising and promotion, publishing, medical
education, public relations, consulting, interactive multimedia, database
marketing and marketing research services.
 
2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
 
  Principles of Combination
 
     The combined financial statements include the accounts of the affiliated
companies. All inter-company balances and transactions have been eliminated.
 
  Revenue Recognition
 
     Substantially all revenues are derived from fees from clients for creative
concept development, production of advertising and marketing materials and the
communication of a client's product message to target markets through the use of
educational projects.
 
     Substantially all revenues from creative fees are recognized when earned
either under monthly retainer agreements or on an actual time incurred basis.
Fees for production are earned when the production materials are completed.
Advanced production billings represent project costs and fees that are billed to
clients as projects progress, and are recognized at completion.
 
     Accounts receivable include fees recognized, project costs, and media and
production costs incurred on behalf of clients, which are paid for by the
Company and rebilled to clients.
 
  Concentration of Credit Risk
 
     The Company provides communication, marketing, advertising and related
services to a wide range of clients who operate mainly in the health care and
food service industries. For the year ended December 31, 1996, the Company had
three clients which constituted approximately 40%, 13% and 9% of total revenues.
In addition, the Company's five largest clients represent 74% of combined
revenues for that period. The Company had three clients which constituted
approximately 37%, 13% and 11% of total 1995 revenues and 24%, 17% and 9% of

total 1994 revenues. As of December 31, 1995 and 1996, primarily all of the
Company's trade accounts receivable were concentrated in companies in the health
care industry. The Company extends credit to all qualified clients, but does not
believe that it is exposed to any undue concentration of credit risk to any
significant degree. The Company maintains reserves for potential credit losses,
but has not experienced any material losses to individual clients or groups of
clients.
 
  Cash and Cash Equivalents
 
     For purposes of the combined balance sheets and combined statements of cash
flows, the Company considers all highly liquid debt instruments purchased with
original maturities of three months or less to be cash equivalents, including
commercial paper and money market mutual funds.
 
                                      F-17
GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

              NOTES TO COMBINED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES--(CONTINUED)

  Unbilled Production Charges
 
     Unbilled production charges consist principally of costs incurred in
producing advertisements and marketing communications for clients. Such amounts
are generally billed to clients when costs are incurred for radio and television
production and when print production is complete.
 
  Furniture, Equipment and Leasehold Improvements
 
     Furniture, equipment and leasehold improvements are stated at cost, net of
accumulated depreciation and amortization. Depreciation and amortization are
computed using the straight-line method over the estimated useful lives of the
assets as follows:
Furniture.................................   5-7 years
Equipment.................................   5-7 years
Leasehold improvements....................   Lesser of lease term or useful life
Income Taxes
 
     The companies comprising the Company (other than Syberactive, which is
treated as a 'C Corporation'), with the consent of the stockholders, elected to
have their Federal and state income taxed as subchapter 'S Corporations.' In
lieu of Federal and certain state corporate income taxes, the shareholders are

taxed on their proportionate share of income, or receive the benefit of any
losses individually. New York City Corporation taxes are provided, if required,
at statutory rates.
 
  Use of Estimates
 
     The preparation of financial statements in conformity with generally
accepted accounting principles requires management to make estimates and
assumptions that affect the amounts reported in the financial statements and
accompanying notes. Actual results could differ from those estimates.
 
  New Accounting Pronouncements
 
     During 1996, the Company adopted Statement of Financial Accounting
Standards No. 121 (SFAS No. 121), 'Accounting for the Impairment of Long-Lived
Assets and Long-Lived Assets to be Disposed of.' This statement requires the
Company to review long-lived assets for impairment whenever events or changes in
circumstances indicate that the carrying amount of an asset may not be
recoverable. The effect of adoption was not material.
 
  Recently Issued Accounting Standards
 
     In March 1997, the Financial Accounting Standards Board issued Statement of
Financial Accounting Standards ('SFAS') No. 128, Earnings Per Share. This
Statement establishes standards for computing and presenting earnings per share
('EPS'), replacing the presentation of currently required primary EPS with a
presentation of Basic EPS. For entities with complex capital structures, the
statement requires the dual presentation of both Basic EPS and Diluted EPS on
the face of the statement of income. Under this new standard, Basic EPS is
computed based on weighted average shares outstanding and excludes any potential
dilution; Diluted EPS reflects potential dilution from the exercise or
conversion of securities into common stock or from other contracts to issue
common stock and is similar to the currently required fully diluted EPS. SFAS
128 is effective for financial statements issued for periods ending after
December 15, 1997, including interim periods, and earlier application is not
permitted.
 
                                      F-18
GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

              NOTES TO COMBINED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
3. FURNITURE, EQUIPMENT AND LEASEHOLD IMPROVEMENTS
 
     Furniture, equipment and leasehold improvements consist of the following:
DECEMBER 31,    DECEMBER 31,      JUNE 30,
                                                                              1995            1996            1997
                                                                          ------------    ------------    ------------
                                                                                                          (UNAUDITED)
Furniture and equipment...........................................      $1,607          $2,117          $2,188
     Leasehold improvements............................................         465             465             460
                                                                             ------          ------          ------
                                                                              2,072           2,582           2,648
     Less: Accumulated depreciation and amortization...................         936           1,340           1,445
                                                                             ------          ------          ------
                                                                             $1,136          $1,242          $1,203
                                                                             ------          ------          ------
                                                                             ------          ------          ------
Depreciation and amortization expense of furniture, equipment and leasehold
improvements for the years ended December 31, 1994, 1995 and 1996 amounted to
approximately $214, $274 and $402, respectively, and for the six months ended
June 30, 1996 and 1997 amounted to approximately $174 and $196, respectively
(unaudited).
 
4. RESTRICTED CASH
 
     In connection with the lease for office space, the Company was required to
establish an Irrevocable Standby Letter of Credit with a face amount of $300.
The Company has set aside a Certificate of Deposit in the amount of $300 as
collateral for the Letter of Credit. The Certificate of Deposit has been
included within Other Assets due to the term of the underlying lease commitment.
 
5. BANK LOANS AND LINE OF CREDIT
 
     The Company has in place a $4,100 credit facility with a bank. The facility
currently consists of: (i) an uncommitted $3,500 line of credit ('Line of
Credit'), (ii) a $300 term note ('Term Note'), and (iii) a $300 irrevocable
letter of credit. The facility is secured by a first security interest in the
Company's personal property and a personal guarantee of several of the
stockholders of the Company. Borrowings under the facility are as follows:
DECEMBER 31,   DECEMBER 31,      JUNE 30,  
                                                                              1995           1996            1997
                                                                          ------------   ------------    ------------
                                                                                                         (UNAUDITED)
Line of Credit.....................................................      $600(a)        $400(a)         $ --
     Term Note/Loan.....................................................        82(b)         223(c)          176
                                                                            ------         ------          ------
                                                                               682            623             176
 

     Less: Current portion..............................................       682            498              78
                                                                            ------         ------          ------
                                                                              $ --           $125            $ 98
                                                                            ------         ------          ------
                                                                            ------         ------          ------
------------------
 
a) Borrowings under the Line of Credit are limited to 80% of eligible trade
   receivables, as defined in the agreement. The Line of Credit matures on July
   31, 1997 and bears interest at prime (8.25% as of December 31, 1996) plus 1%
   per annum. The Line of Credit requires the Company to maintain certain
   financial ratios. As of December 31, 1996, the Company was in compliance with
   all of the provisions of the Line of Credit.
 
b) This represented the outstanding principal balance of borrowings under a $400
   term note to finance certain leasehold improvements. The note bore interest
   at 7.5% per annum and was payable in 48 monthly installments commencing
   October 1992. As of December 31, 1996, such note had been repaid.
 
                                      F-19
GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

              NOTES TO COMBINED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
5. BANK LOANS AND LINE OF CREDIT--(CONTINUED)

c) During February 1996, the bank provided a Term Loan of $300 to finance the
   construction of additional office space. This Term Loan bears interest at
   7.75% per annum and is payable in 36 monthly installments commencing March
   1996.
 
     At December 31, 1996, maturities of debt are as follows:
1997..............................................................   $498
1998..............................................................    106
1999..............................................................     19
6. STOCKHOLDERS' EQUITY
 
     The financial statements are presented on a combined basis. Since there is
no parent-subsidiary relationship, there is no basis for eliminating the equity
accounts of any of the entities. As of December 31, 1995 and 1996, and as of
June 30, 1997 (unaudited), stockholders' equity consisted of the following:
RETAINED EARNINGS/
                                                         COMMON STOCK                  (ACCUMULATED DEFICIT)
                                                  ---------------------------    -----------------------------------
                                        SHARES                     JUNE 30,                                JUNE 30,
COMPANY                                 ISSUED    1995    1996       1997         1995          1996        1997
-------------------------------------   ------    ----    ----    -----------    ------        ------    -----------
                                                                  (UNAUDITED)                            (UNAUDITED)
GHBM.................................    85.25    $192    $192       $ 192       $1,517        $1,540      $ 2,157
Black Cat............................   120.90      89      89          89        2,434         2,655        2,654
MET..................................   120.90       6       6           6          477           847          764
Brand................................   120.90       1       1           1           88            43           49
GHBM, Inc............................   120.90       1       1           1           --            (1)          --
Syberactive..........................   100.00      --       1           1           --            (6)         (37)
                                                  ----    ----    -----------    ------        ------    -----------
                                                  $289    $290       $ 290       $4,516        $5,078      $ 5,587
                                                  ----    ----    -----------    ------        ------    -----------
                                                  ----    ----    -----------    ------        ------    -----------
7. COMMITMENTS
 
  Lease
 
     In 1994, the Company entered into a fifteen year lease for office space in
New York City. The lease is payable in monthly installments which include
certain rent holidays and escalations, which have been accounted for on a
straight-line basis over the life of the lease. As a security deposit, the
Company put in place an Irrevocable Standby Letter of Credit (see Note 4) in the
amount of $300. This amount will decrease on November 1, 1997 to $200 and to
$132 on November 1, 1998. During 1996, the Company terminated a lease agreement
on another property. The cost to terminate the lease was insignificant.
 
     The following is a schedule of the minimum annual lease payments due:
1997...............................................................   $  608
1998...............................................................      690
1999...............................................................      750
2000...............................................................      750
2001...............................................................      750
Thereafter.........................................................    7,337
Total rent expense incurred for the years ended December 31, 1994, 1995 and
1996 was approximately $662, $759 and $814, respectively, and for the six months
ended June 30, 1996 and 1997 was approximately $414 and $394, respectively
(unaudited).
 
                                      F-20
GIRGENTI, HUGHES, BUTLER & MCDOWELL, INC. AND AFFILIATES

              NOTES TO COMBINED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
7. COMMITMENTS--(CONTINUED)

  Employment Agreements
 
     The Company has entered into employment agreements (the 'Agreements') with
certain key employees. The Agreements contain provisions for base salary and
incentives based upon certain performance measures, and are subject to
termination by either party. The aggregate annual minimum base compensation
required by the Agreements is approximately $880.
 
  Employee Benefits
 
     The Company maintains a '401 K' Plan for eligible employees, who have
completed the minimum service requirement of the plan. The Company matches up to
4% of salary for participating employees. For the years ended December 31, 1994,
1995 and 1996, the Company has contributed $64, $105 and $124, respectively, and
for the six months ended June 30, 1996 and 1997, the Company has contributed $60
and $90, respectively (unaudited), to the Plan.
 
8. INTERIM FINANCIAL STATEMENTS
 
     The combined financial statements of Girgenti, Hughes, Butler & McDowell,
Inc. as of and for the six months ended June 30, 1996 and 1997, presented herein
have been prepared by the Company without audit, pursuant to the rules and
regulations of the Securities and Exchange Commission. The financial statements
reflect all adjustments (consisting of only normal recurring adjustments) which,
in the opinion of management, are necessary to present fairly the combined
financial position, results of operations and cash flows of the Company as of
June 30, 1996 and 1997, and for the periods ended. The Company's interim results
may fluctuate as a result of a number of factors and are not necessarily
indicative of the results to be obtained for the full year.
 
9. SUBSEQUENT EVENTS
 
     Pursuant to a Letter of Intent between the Company and Milton Marketing
Group Limited and its subsidiaries ('Milton'), the Company and Milton have
agreed to cause their respective stockholders to enter into a definitive
agreement with Healthworld Corporation ('Healthworld') pursuant to which all
outstanding shares of common stock of each of the companies comprising the
Company and Milton will be exchanged for shares of Healthworld common stock as
of the effective date of the Offering (as defined below) (the 'Consolidation').
Upon consummation of the Consolidation, the entities comprising the Company
(other than Syberactive, which is already treated as a C Corporation) will no
longer be treated as S Corporations.
 
     In connection with the termination of the status of each of the companies

comprising the Company as S Corporations, the Company is currently negotiating
to enter into an agreement which will provide that the Company will, prior to
the consummation of the Consolidation, sell an estimated $2,500 of its accounts
receivable to an unaffiliated financial institution at a negotiated discount
rate. Immediately prior to the consummation of the Consolidation, the Company
will make distributions to its stockholders of approximately $3,500 in the
aggregate from existing cash balances for the payment by such stockholders of
taxes due on S Corporation earnings.
 
     Healthworld is pursuing an initial public offering of its securities (the
'Offering'). The Offering contemplates the sale of 2,100 shares of Healthworld's
common stock at an offering price between $8.00 and $9.50 per share before
underwriting commissions and Offering expenses. Healthworld plans to use the
proceeds of the Offering for working capital and general corporate purposes.
 
                                      F-21
After the execution of definitive agreements to undertake the Consolidation
discussed in Note 11 to the consolidated financial statements of Milton
Marketing Group Limited and Subsidiaries, we expect to be in a position to
render the following audit report.
 
                                                  /s/ Arthur Andersen
                                              ----------------------------
                                                     Arthur Andersen
 
August 29, 1997
 

                    REPORT OF INDEPENDENT PUBLIC ACCOUNTANTS

 
To Milton Marketing Group Limited and Subsidiaries:
 
We have audited the accompanying consolidated balance sheets of Milton Marketing
Group Limited (a United Kingdom corporation, formerly known as Siteinput
Limited) and Subsidiaries as of November 30, 1995 and 1996, and the related
consolidated statements of income, stockholders' equity and cash flows for each
of the three years in the period ended November 30, 1996. These financial
statements are the responsibility of the Company's management. Our
responsibility is to express an opinion on these financial statements based on
our audits.
 
We conducted our audits in accordance with generally accepted auditing
standards. Those standards require that we plan and perform the audit to obtain
reasonable assurance about whether the financial statements are free of material
misstatement. An audit includes examining, on a test basis, evidence supporting
the amounts and disclosures in the financial statements. An audit also includes
assessing the accounting principles used and significant estimates made by
management, as well as evaluating the overall financial statement presentation.
We believe that our audits provide a reasonable basis for our opinion.
 
In our opinion, the financial statements referred to above present fairly, in
all material respects, the financial position of Milton Marketing Group Limited
and Subsidiaries as of November 30, 1995 and 1996, and the results of their
operations and their cash flows for each of the three years in the period ended
November 30, 1996 in conformity with generally accepted accounting principles.
 
Melville, New York
January 27, 1997
     (except with respect to the matters
     discussed in Note 11 as to which
     the date is               , 1997)
 
                                      F-22
MILTON MARKETING GROUP LIMITED

                          CONSOLIDATED BALANCE SHEETS
                       (IN THOUSANDS, EXCEPT SHARE DATA)
NOVEMBER 30,
                                                                                    ----------------     JUNE 30,
                                                                                     1995      1996        1997
                                                                                    ------    ------    -----------
                                                                                                        (UNAUDITED)
ASSETS
Current assets:
  Cash and cash equivalents......................................................   $  511    $   --      $    19
  Accounts receivable............................................................    1,058     3,266        3,510
  Unbilled production charges, at cost...........................................       49        87          273
  Other current assets...........................................................      147       415          581
                                                                                    ------    ------      -------
     Total current assets........................................................    1,765     3,768        4,383
Furniture, equipment and leasehold improvements, net.............................      634       870          948
Goodwill, net of accumulated amortization of $2, $44 and $79, respectively.......      994     1,800        1,707
Other assets.....................................................................        8        49          262
                                                                                    ------    ------      -------
                                                                                    $3,401    $6,487      $ 7,300
                                                                                    ------    ------      -------
                                                                                    ------    ------      -------
 
                      LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities:
  Bank loans and overdrafts......................................................   $   24    $  406      $ 1,211
  Current portion of long-term debt..............................................      107       118          595
  Current portion of capitalized lease obligation................................       74       125           69
  Accounts payable...............................................................      340     1,144        1,538
  Accrued expenses...............................................................      936     1,977        1,418
  Advance billings...............................................................      441       534          684
                                                                                    ------    ------      -------
     Total current liabilities...................................................    1,922     4,304        5,515
Commitments (Note 9)
Long-term debt...................................................................      882       825          291
Capitalized lease obligation.....................................................       78       128          193
Minority interests...............................................................       89       143          268
Other liabilities................................................................       --        83           57
                                                                                    ------    ------      -------
                                                                                     2,971     5,483        6,324
                                                                                    ------    ------      -------
Stockholders' equity:
  Common stock, $1.68 par value, 10,000 shares authorized, and 2 shares issued
     and outstanding.............................................................       --        --           --
  Additional paid-in capital.....................................................       13        13           13
  Retained earnings..............................................................      423       925          914

  Cumulative foreign currency translation adjustments............................       (6)       66           49
                                                                                    ------    ------      -------
     Total stockholders' equity..................................................      430     1,004          976
                                                                                    ------    ------      -------
                                                                                    $3,401    $6,487      $ 7,300
                                                                                    ------    ------      -------
                                                                                    ------    ------      -------
The accompanying notes to consolidated financial statements are an integral part
                            of these balance sheets.

                                      F-23
MILTON MARKETING GROUP LIMITED

                       CONSOLIDATED STATEMENTS OF INCOME
                                 (IN THOUSANDS)
SEVEN MONTHS
                                                                   YEAR ENDED NOVEMBER 30,       ENDED JUNE 30,
                                                                   ------------------------     ----------------
                                                                    1994     1995     1996       1996      1997
                                                                   ------   ------   ------     ------    ------
                                                                                                  (UNAUDITED)
Revenues.........................................................  $2,666   $4,399   $9,895     $5,434    $8,147
                                                                   ------   ------   ------     ------    ------
Operating expenses:
  Salaries and related costs.....................................   1,474    2,531    6,793      3,860     6,333
  Other operating expenses.......................................     802    1,310    2,017        999     1,506
                                                                   ------   ------   ------     ------    ------
                                                                    2,276    3,841    8,810      4,859     7,839
Income from operations...........................................     390      558    1,085        575       308
Interest expense, net............................................      12       15       93         40        62
                                                                   ------   ------   ------     ------    ------
Income before provision for income taxes and minority
  interests......................................................     378      543      992        535       246
Provision for income taxes.......................................     117      159      366        197        91
Minority interests in net earnings of subsidiaries...............      39       68      124         81       126
                                                                   ------   ------   ------     ------    ------
Net income.......................................................  $  222   $  316   $  502     $  257    $   29
                                                                   ------   ------   ------     ------    ------
                                                                   ------   ------   ------     ------    ------
The accompanying notes to consolidated financial statements are an integral part
                              of these statements.

                                      F-24
MILTON MARKETING GROUP LIMITED

                CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY
                                 (IN THOUSANDS)
CUMULATIVE
                                                                   ADDITIONAL                FOREIGN CURRENCY
                                                         COMMON     PAID-IN      RETAINED      TRANSLATION
                                                         STOCK      CAPITAL      EARNINGS      ADJUSTMENTS       TOTAL
                                                         ------    ----------    --------    ----------------    -----
Balance, November 30, 1993............................     $--        $ 13         $101            $ (1)         $ 113
  Net income..........................................     --           --          222              --            222
  Dividends...........................................     --           --         (130)             --           (130)
  Foreign currency translation adjustments............     --           --           --               8              8
                                                           ---        ----         ----            ----          -----
Balance, November 30, 1994............................     --           13          193               7            213
  Net income..........................................     --           --          316              --            316
  Dividends...........................................     --           --          (86)             --            (86)
  Foreign currency translation adjustments............     --           --           --             (13)           (13)
                                                           ---        ----         ----            ----          -----
Balance, November 30, 1995............................     --           13          423              (6)           430
  Net income..........................................     --           --          502              --            502
  Foreign currency translation adjustments............     --           --           --              72             72
                                                           ---        ----         ----            ----          -----
Balance, November 30, 1996............................     --           13          925              66          1,004
  Net income (unaudited)..............................     --           --           29              --             29
  Dividends (unaudited)...............................     --           --          (40)             --            (40)
  Foreign currency translation adjustments
     (unaudited)......................................     --           --           --             (17)           (17)
                                                           ---        ----         ----            ----          -----
Balance, June 30, 1997 (unaudited)....................     $--        $ 13         $914            $ 49          $ 976
                                                           ---        ----         ----            ----          -----
                                                           ---        ----         ----            ----          -----
The accompanying notes to consolidated financial statements are an integral part
                              of these statements.

                                      F-25
MILTON MARKETING GROUP LIMITED

                     CONSOLIDATED STATEMENTS OF CASH FLOWS
                                 (IN THOUSANDS)
YEAR ENDED             SEVEN MONTHS
                                                                              NOVEMBER 30,           ENDED JUNE 30,
                                                                         -----------------------     ---------------
                                                                         1994    1995     1996        1996     1997
                                                                         -----   -----   -------     -------   -----
                                                                                                       (UNAUDITED)
Cash flows from operating activities:
  Net income...........................................................  $ 222   $ 316   $   502     $   257   $  29
    Adjustments to reconcile net income to net cash
    provided by operating activities:
      Depreciation and amortization....................................    114     136       225         100     121
      Minority interest in net earnings................................     39      68       124          81     126
      (Gain)/loss on sale of fixed assets..............................    (24)      1        18          --      --
    Changes in operating assets and liabilities, net of effect of
    acquisitions:
      Accounts receivable..............................................    418    (138)   (1,456)     (2,197)   (244)
      Unbilled production charges......................................    538      28       (21)       (193)   (186)
      Other current assets.............................................     --     (22)     (166)         (9)   (166)
      Other assets.....................................................     --      --        --          --    (213)
      Accounts payable.................................................   (536)   (614)     (359)        640     394
      Accrued expenses.................................................      7     763       876         833    (487)
      Advance billings.................................................   (502)     74        50         380     150
      Other liabilities................................................     --      --        18          60     (26)
                                                                         -----   -----   -------     -------   -----
Net cash provided by (used in) operating activities....................    276     612      (189)        (48)   (502)
                                                                         -----   -----   -------     -------   -----
Cash flows from investing activities:
  Net purchase price of acquisitions (Note 3)..........................     --    (639)     (242)       (215)     --
  Capital expenditures, net............................................    (95)   (203)     (214)        (66)    (72)
  Proceeds from the sale of fixed assets...............................     58      63        50          --      --
                                                                         -----   -----   -------     -------   -----
Net cash (used in) investing activities................................    (37)   (779)     (406)       (281)    (72)
                                                                         -----   -----   -------     -------   -----
Cash flows from financing activities:
  Payment of majority stockholder dividends............................   (130)    (86)       --          --      --
  Payment of minority interest shareholders dividends..................    (23)    (15)       --          --     (55)
  Proceeds from bank overdraft.........................................     --      --       309         (23)    805
  Repayment of bank loans..............................................     --      --      (131)        (27)    (57)
  Proceeds from bank loans.............................................     --     613        --          --      --
  Capital lease repayments.............................................    (88)   (152)      (77)        (21)    (83)
                                                                         -----   -----   -------     -------   -----
Net cash (used in) provided by financing activities....................   (241)    360       101         (71)    610
                                                                         -----   -----   -------     -------   -----
Effect of exchange rate changes on cash................................     12     (14)      (17)         22     (17)
                                                                         -----   -----   -------     -------   -----
Net increase/(decrease) in cash and cash equivalents...................     10     179      (511)       (378)     19
Cash and cash equivalents at beginning of year.........................    322     332       511         511      --
                                                                         -----   -----   -------     -------   -----
Cash and cash equivalents at end of year...............................  $ 332   $ 511   $    --     $   133   $  19
                                                                         -----   -----   -------     -------   -----
                                                                         -----   -----   -------     -------   -----

Supplemental disclosure of cash flow information:
  Cash paid for taxes..................................................  $ 113   $ 151   $    67     $    --   $ 262
                                                                         -----   -----   -------     -------   -----
                                                                         -----   -----   -------     -------   -----
  Cash paid for interest...............................................  $  21   $  22   $    88     $    40   $  62
                                                                         -----   -----   -------     -------   -----
                                                                         -----   -----   -------     -------   -----
The accompanying notes to consolidated financial statements are an integral part
                              of these statements.

                                      F-26
MILTON MARKETING GROUP LIMITED

                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
1. ORGANIZATION AND BUSINESS
 
     In 1997, the company formerly known as Siteinput Limited changed its name
to Milton Marketing Group Limited. Milton Marketing Group Limited ('Milton'), a
United Kingdom corporation, was formed in October 1995. Through its predecessor,
Milton Marketing Limited, Milton, together with its subsidiaries (Milton and its
subsidiaries are collectively referred to as the 'Company'), provides a broad
range of integrated marketing services including strategic planning, product
positioning, database marketing, field marketing, new product development,
advertising, public relations, marketing research, and sales promotion. Milton
is comprised of its wholly-owned subsidiary Effective Sales Personnel Limited
('ESP') and its majority-owned subsidiaries, Milton Marketing Limited ('MML'),
Headcount Limited ('HL'), PDM Communications Limited ('PDM') and Milton Cater
Limited ('MCL').
 
2. SIGNIFICANT ACCOUNTING POLICIES
 
  Principles of Consolidation
 
     The accompanying consolidated financial statements include the accounts of
the Company and its wholly-owned and majority-owned subsidiaries. All
intercompany accounts and transactions have been eliminated.
 
  Foreign Currency Translation
 
     All assets and liabilities of the Company are translated into United States
dollars from United Kingdom Pound Sterling at period-end exchange rates. Income
and expense items are translated at average exchange rates prevailing during
each fiscal period. The resulting translation adjustments are recorded as a
separate component of stockholders' equity.
 
  Revenue Recognition
 
     Substantially all revenues are derived from fees from clients for creative
concept development, production of advertising and marketing materials,
consulting on the market positioning of pharmaceutical products, the supply of
long and short-term personnel for client promotional purposes and the provision
of public relations services to public health service institutions.
 
     Substantially all revenues from creative fees are recognized when earned
either under monthly retainer agreements or on an actual time incurred basis.
Fees for production are earned when the production materials are completed.
Advanced production billings represent project costs and fees that are billed to
clients as projects progress and are recognized at completion. Income for field
marketing support is recognized as services are provided.
 
     Accounts receivable include fees recognized, project costs, and media and

production costs incurred on behalf of clients, which are paid for by the
Company and billed to clients. The Company records gross contract revenues for
contract sales services and the related direct costs are included in salaries
and related costs on the accompanying consolidated statements of income.
 
  Concentration of Credit Risk
 
     The Company provides services to a range of clients operating mostly in the
healthcare, food and beverage and communication industries. For the year ended
November 30, 1996, the Company had one client which constituted approximately
13% of total revenues. In addition, the Company's five largest clients
represented 45% of total revenues for that period. The Company had one client
which constituted approximately 16% and 25% of total 1995 and 1994 revenues,
respectively. The Company extends credit to all qualified clients, but does not
believe that it is exposed to any undue concentration of credit risk to any
significant degree. The Company maintains reserves for potential credit losses,
but has not experienced any material losses to individual clients or groups of
clients.
 
                                      F-27
MILTON MARKETING GROUP LIMITED

            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
2. SIGNIFICANT ACCOUNTING POLICIES--(CONTINUED)

  Cash and Cash Equivalents
 
     For purposes of the consolidated balance sheets and consolidated statements
of cash flows, the Company considers all highly liquid debt instruments
purchased with original maturities of three months or less to be cash
equivalents, including commercial paper and money market mutual funds.
 
  Unbilled Production Charges
 
     Unbilled production charges consists principally of costs incurred in
producing marketing communications for clients and field marketing personnel to
be billed. Such amounts will be billed to clients at either a defined stage of
the project or when production is complete.
 
  Furniture, Equipment and Leasehold Improvements
 
     Furniture, equipment and leasehold improvements are stated at cost, net of
accumulated depreciation and amortization. Depreciation and amortization are
computed using both accelerated and straight-line methods over the following
periods:
Furniture.................................   4-10 years
Equipment.................................   4-14 years
Motor Vehicles............................   4-8 Years
Leasehold Improvements....................   Lesser of lease term or useful life
Equipment Held under Capital Leases
 
     Assets held under capital leases is accounted for in accordance with
Statement of Financial Accounting Standards No. 13, 'Accounting for Leases,' and
recorded in Property, Plant and Equipment. The present value of the related
liability is included in capitalized lease obligations.
 
  Goodwill
 
     Goodwill represents the Company's excess cost over net assets acquired and
is being amortized on a straight-line basis over the estimated useful life of
the assets. Amounts recognized to date have been amortized over 30 years from
the original date of acquisition. Amortization expense of goodwill for the years
ended November 30, 1994, 1995 and 1996 amounted to $0, $2 and $42, respectively,
and for the seven months ended June 30, 1996 and 1997 amounted to $23 and $35,
respectively (unaudited).
 
     During 1996, the Company adopted Statement of Financial Accounting
Standards No. 121 (SFAS No. 121), 'Accounting for the Impairment of Long-Lived
Assets and Long-Lived Assets to be Disposed of.' This statement requires the
Company to review long-lived assets, including certain intangibles and goodwill,
for impairment whenever events or changes in circumstances indicate that the
carrying amount of an asset may not be recoverable. The effect of adoption was
not material.
 
  Income Taxes
 
     The Company accounts for income taxes in accordance with Statement of
Financial Accounting Standards No. 109, 'Accounting for Income Taxes.' This
statement requires a liability approach for measuring deferred taxes based on
temporary differences between the financial statement and income tax bases of
assets and liabilities existing at each balance sheet date using enacted rates
for the years in which the taxes are expected to be paid or recovered. The
Company has not recorded any deferred tax assets or liabilities as any
differences between book and income tax recognition are immaterial.
 
                                      F-28
MILTON MARKETING GROUP LIMITED

            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
2. SIGNIFICANT ACCOUNTING POLICIES--(CONTINUED)

  Use of Estimates
 
     The preparation of financial statements in conformity with generally
accepted accounting principles requires management to make estimates and
assumptions that affects the amounts reported in the financial statements and
accompanying notes. Actual results could differ from those estimates.
 
  Recently Issued Accounting Standards
 
     In March 1997, the Financial Accounting Standards Board issued Statement of
Financial Accounting Standards ('SFAS') No. 128, Earnings Per Share. This
statement establishes standards for computing and presenting earnings per share
('EPS'), replacing the presentation of currently required primary EPS with a
presentation of Basic EPS. For entities with complex capital structures, the
statement requires the dual presentation of both Basic EPS and Diluted DPS on
the face of the statement of income. Under this new standard, Basic EPS is
computed based on weighted average shares outstanding and excludes any potential
dilution; Diluted EPS reflects potential dilution from the exercise or
conversion of securities into common stock or from other contracts to issue
common stock and is similar to the currently required fully diluted EPS. SFAS
128 is effective for financial statements issued for periods ending after
December 15, 1997, including interim periods, and earlier application is not
permitted.
 
3. ACQUISITIONS OF BUSINESSES
 
  Effective Sales Personnel Limited
 
     In November 1995, the Company acquired all of the outstanding stock of ESP
for a purchase price of $1,130. The purchase price was funded by cash and a $462
note due March 1998.
 
  Milton Cater Limited
 
     MCL was formed in April 1996, and the Company acquired 51% of its equity in
May 1996. The remaining 49% of MCL's equity is owned by a key employee and must
be purchased by the Company on the earliest of May 23, 2001, the sale or
disposal of MCL or the Company, or the Company being the subject of an initial
public offering. The purchase price is set at 60% of defined average annual
Gross Profits of MCL, as defined in the agreement, in excess of $588 for the
three years prior to purchase, subject to a maximum purchase price of $504. At
November 30, 1996 the purchase price would be immaterial.
 
  Milton Marketing Limited
 
     In April 1996, the Company acquired an additional 7.5% interest in MML for
$234, which increased the Company's interest in MML to 92.5%.
 
  PDM Communications Limited
 
     In November 1996, the Company acquired a 75% interest in PDM for a cash
purchase price of $32.
 
     The minority stockholder has a put option and the Company has a call option

with respect to the remaining 25% of PDM shares not owned by the Company. The
stockholder put option would require payment of 18.5% of Gross Income of PDM, as
defined in the agreement, for the period from November 26, 1996 to date of
exercise. The Company's call option would require payment on 25% of Gross Income
to date of exercise. The stockholder put option is exercisable at any time up to
November 30, 1998, provided that PDM has generated positive Gross Income, after
personnel costs during the period. The Company's call option is exercisable if a
certain key employee leaves PDM, or if PDM or the Company is sold or the subject
of an initial public offering.
 
                                      F-29
MILTON MARKETING GROUP LIMITED

            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
3. ACQUISITIONS OF BUSINESSES--(CONTINUED)

     As a result of the three acquisitions discussed above, goodwill was
recorded as follows:
ESP      MML       PDM
                                                                               ------    ----    -------
Assets......................................................................   $  346    $ --    $   717
Minority share of net assets acquired.......................................       --      46         --
Goodwill....................................................................    1,027     188        523
Liabilities.................................................................     (243)     --     (1,208)
                                                                               ------    ----    -------
  Total purchase price......................................................   $1,130    $234    $    32
                                                                               ------    ----    -------
                                                                               ------    ----    -------
Pro Forma Results of Operations
 
     Summarized below are the unaudited pro forma results of operations of the
Company as though the ESP acquisition had occurred at the beginning of 1994 and
the MML and PDM acquisitions had occurred at the beginning of 1995. Adjustments
have been made for pro forma income taxes and amortization of goodwill related
to these transactions.
YEAR ENDED NOVEMBER 30,
                                                                             ---------------------------
Pro Forma:                                                                    1994      1995      1996
                                                                             ------    ------    -------
Revenues................................................................   $5,609    $6,634    $10,282
  Net income..............................................................      357       392        135
These pro forma results of operations are not necessarily indicative of the
actual results of operations that would have occurred had the acquisitions been
made at the beginning of 1994 or 1995 or of results which may occur in the
future.
 
4. FURNITURE, EQUIPMENT AND LEASEHOLD IMPROVEMENTS
 
     Motor vehicles, furniture, equipment and leasehold improvements consist of
the following:
NOVEMBER 30,    NOVEMBER 30,       JUNE 30,
                                                                    1995            1996            1997
                                                                ------------    ------------    -------------
                                                                                                 (UNAUDITED)
Motor vehicles...............................................      $  204          $  265         $   265
Furniture and equipment......................................         670             996           1,070
  Leasehold improvements.....................................         126             163             163
Equipment held under capital leases..........................         284             395             485
                                                                   ------          ------         -------
                                                                    1,284           1,819           1,983
Less: Accumulated depreciation and amortization..............         650             949           1,035
                                                                   ------          ------         -------
                                                                   $  634          $  870         $   948
                                                                   ------          ------         -------
                                                                   ------          ------         -------
Depreciation and amortization expense of furniture, equipment and leasehold
improvements for the years ended November 30, 1994, 1995 and 1996 amounted to
approximately $114, $134 and $183, respectively, and for the seven months ended
June 30, 1996 and 1997 amounted to $84 and $106, respectively (unaudited).
 
                                      F-30
MILTON MARKETING GROUP LIMITED

            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
5. ACCRUED EXPENSES
 

     Major components of accrued expenses included:
NOVEMBER 30,    NOVEMBER 30,     JUNE 30,
                                                                    1995            1996           1997
                                                                ------------    ------------    ----------
                                                                                                (UNAUDITED)
Value added and payroll taxes................................      $  445          $1,155         $   836
Payroll......................................................          --             356             387
Directors fees...............................................         130              --              --
Other........................................................         361             466             195
                                                                   ------          ------         -------
                                                                   $  936          $1,977         $ 1,418
                                                                   ------          ------         -------
                                                                   ------          ------         -------
6. BANK LOANS AND OVERDRAFT
 
     The Company has the following loans outstanding:
NOVEMBER 30,    NOVEMBER 30,     JUNE 30,
                                                                    1995            1996           1997
                                                                ------------    ------------    ----------
                                                                                                (UNAUDITED)
Term loan(a).................................................      $  535          $  470         $   407
Business development loan(b).................................          57              38              23
Overdraft facility(c)........................................          --             379           1,211
4% loan notes(d).............................................         421             462             456
                                                                   ------          ------         -------
                                                                    1,013           1,349           2,097
Less: Current portion........................................         131             524           1,806
                                                                   ------          ------         -------
                                                                   $  882          $  825         $   291
                                                                   ------          ------         -------
                                                                   ------          ------         -------
------------------
a) During November 1995, a bank provided a term loan of $588 to the Company
   which bears interest at the UK base rate (6% as of November 30, 1996) plus 2%
   per annum and is payable in installments of $58 every May and November with
   the final installment due in November 2000. The term loan requires the
   Company to maintain certain financial covenants. As of November 30, 1996, the
   Company was in compliance with all of the provisions of the term loan.
 
b) This loan bears interest at 10.5% per annum and matures in April 1998.

 
c) The Company has in place a $672 overdraft facility with a bank which bears
   interest at the UK base rate plus 2% per annum. As of November 30, 1996, the
   outstanding balance was approximately $379. At June 30, 1997, the bank has
   allowed the Company to exceed the overdraft facility limit. The Company is
   currently negotiating with the bank to increase the limit of the facility
   (unaudited).
 
d) In connection with the ESP acquisition the Company has issued a $462, 4%
   unsecured note, which is payable in March 1998.
 
     At November 30, 1996, maturities of debt are as follows:
1997...........................................................   $524
1998...........................................................    593
1999...........................................................    116
2000...........................................................    116
7. CAPITALIZED LEASE OBLIGATION
 
     The Company enters into leases for computer equipment and motor vehicles.
The lease payments are payable monthly on a straight-line basis. The assets
relating to the leases are capitalized and amortized over a period approximating
the lease period.
 
                                      F-31
MILTON MARKETING GROUP LIMITED

            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
7. CAPITALIZED LEASE OBLIGATION--(CONTINUED)

     Minimum future lease payments under capital leases as of November 30 are as
follows:
1997.................................................................   $141
1998.................................................................    101
1999.................................................................     44
                                                                        ----
Total minimum lease payments.........................................    286
Less: Amount representing interest...................................     33
                                                                        ----
Present value of minimum lease payments..............................   $253
                                                                        ----

                                                                        ----
Interest rates on capitalized leases vary from 11% to 15% and are imputed
based on the lessor's implicit rate of return.
 
8. INCOME TAXES
 
     The following table reconciles the U.K. Federal statutory rate to the
Company's effective income tax rate for the years ended November 30, 1994, 1995
and 1996:
NOVEMBER 30,
                                                                                      --------------------
                                                                                      1994    1995    1996
                                                                                      ----    ----    ----
Statutory rate.....................................................................    33%     33%     33%
Nondeductible expenses.............................................................    ---     ---      4%
Small and marginal company rate relief.............................................    (2%)    (4%)    ---
                                                                                       ---     ---     ---
Effective rate.....................................................................    31%     29%     37%
                                                                                       ---     ---     ---
                                                                                       ---     ---     ---
The Company has not recorded any deferred tax assets or liabilities as any
differences between book and income tax recognition are immaterial.
 
9. COMMITMENTS
 
     The Company has entered into various leases for property. All leases are
payable in quarterly installments, and are accounted for on a straight line
basis over the term of the lease.
 
     The following is a schedule of the minimum annual lease payments due:
1997.......................................................................   $  393
1998.......................................................................      393
1999.......................................................................      393
2000.......................................................................      393
2001.......................................................................      393
Thereafter.................................................................    2,048
Total rent expense incurred for the years ended November 30, 1994, 1995 and
1996 was approximately $116, $107 and $229, respectively, and for the seven
months ended June 30, 1996 and 1997 was approximately $118 and $225,
respectively (unaudited).
 

  Employment Agreements
 
     The Company has entered into employment agreements (the 'Agreements') with
certain key employees. The Agreements contain provisions for base salary and
incentives based upon certain performance measures, and are subject to
termination by either party. The aggregate annual minimum base compensation
required by the Agreements is approximately $200.
 
                                      F-32
MILTON MARKETING GROUP LIMITED

            NOTES TO CONSOLIDATED FINANCIAL STATEMENTS--(CONTINUED)
 
                     (IN THOUSANDS, EXCEPT PER SHARE DATA)
 
9. COMMITMENTS--(CONTINUED)

  Employee Benefits
 
     The Company makes non-contractual payments into the personal pension plans
of various directors and senior management. For the years ended November 30,
1994, 1995, and 1996, the Company has contributed $56, $74, and $41,
respectively, and for the seven months ended June 30, 1996 and 1997, the Company
has contributed $34 and $37, respectively (unaudited).
 
10. INTERIM FINANCIAL STATEMENTS
 
     The consolidated financial statements of Milton Marketing Group Limited as
of and for the seven months ended June 30, 1996 and 1997, presented herein have
been prepared by the Company without audit, pursuant to the rules and
regulations of the Securities and Exchange Commission. The financial statements
reflect all adjustments (consisting of only normal recurring adjustments) which,
in the opinion of management, are necessary to present fairly the combined
financial position, results of operations and cash flows of the Company as of
June 30, 1996 and 1997, and for the periods then ended. The Company's interim
results may fluctuate as a result of a number of factors and are not necessarily
indicative of the results to be obtained for the full year.
 
11. SUBSEQUENT EVENTS
 
     Pursuant to a Letter of Intent between the Company and Girgenti, Hughes,
Butler & McDowell, Inc. and its affiliated entities ('GHB&M'), the Company and
GHB&M have agreed to cause their respective stockholders to enter into
definitive agreements with Healthworld Corporation ('Healthworld') pursuant to
which all outstanding shares of common stock of each of the companies comprising
the Company and GHB&M will be exchanged for shares of Healthworld common stock
as of the effective date of the Offering (as defined below) (the
'Consolidation'). Concurrent with the Consolidation, the four stockholders
holding all of the minority interests in the entities comprising the Company
will contribute their interests in such respective companies to Healthworld in
exchange for shares of common stock of Healthworld.

 
     Healthworld is pursuing an initial public offering of its securities (the
'Offering'). The Offering contemplates the sale of 2,100 shares of Healthworld's
common stock at an offering price between $8.00 and $9.50 per share before
underwriting commissions and Offering expenses. Healthworld plans to use the
proceeds of the Offering for working capital and general corporate purposes.
 
                                      F-33
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 
     NO UNDERWRITER, DEALER, SALESMAN OR OTHER PERSON HAS BEEN AUTHORIZED TO
GIVE ANY INFORMATION OR TO MAKE ANY REPRESENTATIONS IN CONNECTION WITH THIS
OFFERING, OTHER THAN THOSE CONTAINED IN THIS PROSPECTUS, AND, IF GIVEN OR MADE,
SUCH INFORMATION OR REPRESENTATIONS MUST NOT BE RELIED UPON AS HAVING BEEN
AUTHORIZED BY THE COMPANY OR THE UNDERWRITERS. THIS PROSPECTUS DOES NOT
CONSTITUTE AN OFFER TO SELL, OR A SOLICITATION OF AN OFFER TO BUY, ANY
SECURITIES OFFERED HEREBY BY ANYONE IN ANY JURISDICTION IN WHICH SUCH OFFER OR
SOLICITATION IS NOT AUTHORIZED OR IN WHICH THE PERSON MAKING SUCH OFFER OR
SOLICITATION IS NOT AUTHORIZED OR IN WHICH THE PERSON MAKING SUCH OFFER OR
SOLICITATION IS NOT QUALIFIED TO DO SO OR TO ANYONE TO WHOM IT IS UNLAWFUL TO
MAKE SUCH OFFER OR SOLICITATION. NEITHER THE DELIVERY OF THIS PROSPECTUS NOR ANY
SALE MADE HEREUNDER SHALL, UNDER ANY CIRCUMSTANCES, CREATE ANY IMPLICATION THAT
THE INFORMATION CONTAINED HEREIN IS CORRECT AS OF ANY TIME SUBSEQUENT TO THE
DATE OF THIS PROSPECTUS.
 
                            ------------------------
 
                               TABLE OF CONTENTS
PAGE
                                                     ----
Prospectus Summary................................     3
Risk Factors......................................     6
The Consolidation.................................    11
Use of Proceeds...................................    12
Dividend Policy...................................    12
Dilution..........................................    13
Capitalization....................................    14
Selected Pro Forma Combined Financial
  Information.....................................    15
Selected Financial Information of GHB&M
  and Milton......................................    16
Management's Discussion and Analysis of Financial
  Condition and Results of Operations.............    17
Business..........................................    24
Management........................................    33

Certain Relationships and Related
  Transactions....................................    38
Principal Stockholders............................    39
Description of Capital Stock......................    40
Shares Eligible for Future Sale...................    42
Underwriting......................................    43
Legal Matters.....................................    44
Experts...........................................    44
Forward Looking Statement.........................    44
Additional Information............................    45
Index to Financial Statements.....................   F-1
------------------------
 
     UNTIL              , 1997 (25 DAYS AFTER THE DATE OF THIS PROSPECTUS), ALL
DEALERS EFFECTING TRANSACTIONS IN THE COMMON STOCK, WHETHER OR NOT PARTICIPATING
IN THIS DISTRIBUTION, MAY BE REQUIRED TO DELIVER A PROSPECTUS. THIS REQUIREMENT
IS IN ADDITION TO THE OBLIGATION OF DEALERS TO DELIVER A PROSPECTUS WHEN ACTING
AS UNDERWRITERS AND WITH RESPECT TO THEIR UNSOLD ALLOTMENTS OR SUBSCRIPTIONS.
 
                                2,100,000 SHARES
                                     [LOGO]
                                  HEALTHWORLD
                                  CORPORATION
                                  COMMON STOCK
                            ------------------------
                                   PROSPECTUS
                            ------------------------
                                UNTERBERG HARRIS
                             PENNSYLVANIA MERCHANT
                                   GROUP LTD
 
                                           , 1997
 
                       ---------------------------------------------------------
                       ---------------------------------------------------------
                       ---------------------------------------------------------
                       ---------------------------------------------------------
PART II
                     INFORMATION NOT REQUIRED IN PROSPECTUS
 
ITEM 13. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION
 
     Set forth below is an estimate of the approximate amount of fees and
expenses (other than underwriting commissions and discounts) payable by the
Registrant in connection with the issuance and distribution of the Common Stock
pursuant to the Prospectus contained in this Registration Statement.
APPROXIMATE
                                                                 AMOUNT

                                                               -----------
Securities and Exchange Commission registration fee.........    $6,952.27
NASD filing fee.............................................     2,794.25
Nasdaq National Market listing fee..........................       *
Accountants' fees and expenses..............................       *
Blue Sky fees and expenses..................................       --
Legal fees and expenses.....................................       *
Transfer Agent and Registrar fees and expenses..............       *
Printing and engraving expenses.............................       *
Miscellaneous...............................................       *
                                                               -----------
     Total..................................................    $  *
                                                               -----------
                                                               -----------
------------------
* To be completed by amendment.
 
ITEM 14. INDEMNIFICATION OF DIRECTORS AND OFFICERS
 
     The Registrant's Certificate of Incorporation and By-laws provide that the
Registrant shall indemnify its directors to the full extent permitted by the
General Corporation Law of the State of Delaware (the 'DGCL') and may indemnify
its officers and employees to such extent, except that the Registrant shall not
be obligated to indemnify any such person (i) with respect to proceedings,
claims or actions initiated or brought voluntarily by any such person and not by
way of defense, or (ii) for any amounts paid in settlement of an action
indemnified against by the Registrant without the prior written consent of the
Registrant without the prior written consent of the Registrant. The Registrant
intends to enter into indemnity agreements with each of its directors. These
agreements may require the Registrant, among other things, to indemnify such
directors against certain liabilities that may arise by reason of their status
or service as directors, and to advance expenses to them as they are incurred,
provided that they undertake to repay the amount advanced if it is ultimately
determined by a court that they are not entitled to indemnification, and to
obtain directors' liability insurance if available on reasonable terms.
 
     In addition, the Registrant's Certificate of Incorporation provides that a
director of the Registrant shall not be personally liable to the Registrant or
its stockholders for monetary damages for breach of his or her fiduciary duty as
director, except for liability (i) for any breach of the director's duty of
loyalty to the Registrant or its stockholders, (ii) for acts or omissions not in
good faith or which involve intentional misconduct or a knowing violation of
law, (iii) for willful or negligent conduct in paying dividends or repurchasing
stock out of other than lawfully available funds or (iv) for any transaction
from which the director derives an improper personal benefit.
 
     Reference is made to Section 145 of the DGCL which provides for
indemnification of directors and officers in certain circumstances.
 
ITEM 15. RECENT SALES OF UNREGISTERED SECURITIES
 

     In connection with the Consolidation, the Registrant will, as of the date
of this Registration Statement, issue an aggregate of 5,000,000 shares of Common
Stock to the stockholders of GHB&M and Milton in exchange for all of their stock
of GHB&M and Milton. Such transaction will be effected in reliance upon the
exemption from the registration of the Securities Act contained in Section 4(2)
of the Securities Act and the rules and regulations promulgated thereunder on
the basis that such transaction did not involve any public offering. No
underwriters
 
                                      II-1
were engaged with respect to such transaction and no underwriting discounts or
commissions will be paid in connection with the sale of such securities.
 
ITEM 16. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES
 
     (a) Exhibits
 
     The following documents are filed as part of this Registration Statement:
EXHIBIT
  NUMBER     DESCRIPTION
----------   --------------------------------------------------------------------------------------------------------
1.01      --   Form of Underwriting Agreement between the Registrant and Unterberg Harris and Pennsylvania
                   Merchant Group Ltd, as representatives of several underwriters.
    2.01      --   Letter of Intent between Girgenti, Hughes, Butler & McDowell, Inc. ('GH') and its affiliated
                   entities and Milton Marketing Group Limited and its subsidiaries, dated November 14, 1996, as
                   amended July 24, 1997.
    2.02      --   Form of Agreement and Plan of Organization by and among the Registrant, Steven Girgenti, Francis
                   Hughes, William Butler and Herbert Ehrenthal.
    2.03      --   Form of Agreement and Plan of Organization between the Registrant and William Leslie Milton.
    2.04      --   Form of Agreement and Plan of Organization by and between the Registrant and minority
                   stockholders.
    3.01      --   Restated Certificate of Incorporation of the Registrant.
    3.02      --   Amended and Restated Bylaws of the Registrant.
    4.01*     --   Specimen Common Stock Certificate.
    5.01*     --   Opinion of Rosenman & Colin LLP.
   10.01      --   Term Loan Facility, dated November 6, 1995, by and between Siteinput Limited (n/k/a Milton
                   Marketing Group Limited) and The Bank of Scotland plc., as amended by letter dated July 23, 1997.
   10.02      --   Line of Credit between The Chase Manhattan Bank, N.A. ('Chase') and GH and each of its affiliated
                   entities, dated January 22, 1996.
   10.03      --   Line of Credit between Chase and GH and each of its affiliated entities, dated January 17, 1997.
   10.04      --   Promissory Note made by GH and its affiliated entities for the benefit of Chase, dated January 31,
                   1996.
   10.05*     --   Registrant's 1997 Incentive Stock Option Plan.
10.06*     --   Employment Agreement by and between the Registrant and Steven Girgenti.
   10.07*     --   Employment Agreement by and between the Registrant and William Leslie Milton.

   10.08*     --   Employment Agreement by and between the Registrant and William Butler.
   10.09*     --   Employment Agreement by and between the Registrant and Herbert Ehrenthal.
   10.10*     --   Employment Agreement by and between the Registrant and Francis Hughes.
   10.11      --   Employment Agreement by and between the Registrant and Stuart Diamond.
   10.12      --   License Agreement between the Registrant and Healthworld, B.V.
   10.13      --   Lease for office space located at 100 Avenue of the Americas, New York, NY, between The Rector,
                   Church-Wardens and Vestrymen of Trinity Church in the City of New York and GH, dated July 15,
                   1994.
   10.14      --   Agreement for the sale and purchase of share capital of Effective Sales Personnel Limited between
                   Gloria Olive Sargent and Siteinput Limited, dated November 8, 1995.
------------------
* To be filed by amendment.
 
                                      II-2
EXHIBIT
  NUMBER     DESCRIPTION
----------   --------------------------------------------------------------------------------------------------------
   10.15      --   Supplemental Agreement relating to the sale and purchase of share capital of Effective Sales
                   Personnel Limited between Gloria Olive Sargent and Siteinput Limited, dated November 29, 1996.
10.16      --   Agreement for the sale and purchase of shares in PDM Communications Limited among Leonard Moreton,
                   Lizabeth Jenny Moreton, Leonard Moreton & Co. and Siteinput Limited, dated November 26, 1996.
   10.17      --   Agreement for the sale and purchase of shares in PDM Communications Limited between William
                   Annandale and Siteinput Limited, dated November 21, 1996.
   10.18      --   Joint Venture Agreement between Siteinput Limited and Claire Denise Cater dated May 23, 1996.
   10.19      --   Share Sale Agreement between Wendy Carter and Siteinput Limited dated April 4, 1996.
   10.20      --   Overdraft Facility, dated November 6, 1995, between Siteinput Limited and The Bank of Scotland
                   plc.
   21.01      --   Subsidiaries of the Registrant.
   23.01      --   Consent of Arthur Andersen LLP.
   23.02*     --   Consent of Rosenman & Colin LLP (included in Exhibit 5.01).
   24.01      --   Power of attorney (included on page II-4).
   27.01      --   Financial Data Schedule.
   27.02      --   Financial Data Schedule.
   27.03      --   Financial Data Schedule.
   27.04      --   Financial Data Schedule.
   27.05      --   Financial Data Schedule.
   27.06      --   Financial Data Schedule.
   27.07      --   Financial Data Schedule.
   27.08      --   Financial Data Schedule.
   99.01      --   Consents of Nominee Directors.
(b) Financial Statement Schedule
 
        None.
 
ITEM 17. UNDERTAKINGS
 

     The Registrant hereby undertakes:
 
          (1) To provide to the Underwriters at the closing specified in the
     underwriting agreement, certificates in such denominations and registered
     in such names as required by the Underwriters to permit prompt delivery to
     each purchaser.
 
          (2) For purposes of determining any liability under the Securities
     Act, the information omitted from the form of prospectus filed as part of
     this Registration Statement in reliance upon Rule 430A and contained in a
     form of prospectus filed by the Registrant pursuant to Rule 424(b)(1) or
     (4) or 497(h) under the Securities Act shall be deemed to be part of this
     Registration Statement as of the time it was declared effective.
 
          (3) For the purpose of determining any liability under the Securities
     Act, each post-effective amendment that contains a form of prospectus shall
     be deemed to be a new registration statement relating to the securities
     offered therein, and the offering of such securities at that time shall be
     deemed to be the initial bona fide offering thereof.
 
     Insofar as indemnification for liabilities arising under the Securities Act
may be permitted to directors, officers and controlling persons of the
Registrant pursuant to the applicable provisions of the DGCL, or

                                      II-3
otherwise, the Registrant has been advised that in the opinion of the
Commission, such indemnification is against public policy as expressed in the
Securities Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
Registrant of expenses incurred or paid by a director, officer or controlling
person of the Registrant in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act and will be governed by the final adjudication of such issue.
 
                                      II-4
SIGNATURES
 
     Pursuant to the requirements of the Securities Act of 1933, the Registrant
has duly caused this Registration Statement to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of New York, State of New
York, on the 29th day of August 1997.
 
                                          HEALTHWORLD CORPORATION
 
                                          By: ________/s/ STEVEN GIRGENTI_______
                                                       Steven Girgenti
                                                 Chairman of the Board and
                                                  Chief Executive Officer
 
                               POWER OF ATTORNEY
 

     Know all men by these presents, that each person whose signature appears
below constitutes and appoints Steven Girgenti and William Leslie Milton and
each of them singly, his true and lawful attorney-in-fact and agent, with full
power of substitution and resubstitution, for him and in his name, place and
stead, in any and all capacities (including his capacity as a director and
officer of Healthworld Corporation) to sign any and all amendments (including
post-effective amendments) to this Registration Statement (and in addition, any
registration statement filed pursuant to 462(b) under the Securities Act of
1933, for the offering to which this Registration Statement relates) and to file
the same, with all exhibits thereto, and other documents in connection
therewith, with the Securities and Exchange Commission, granting unto each said
attorney-in-fact and agent, full power and authority to do and perform each and
every act and thing requisite and necessary to be done in and about the
premises, as fully to all intents and purposes as he might or could do in
person, hereby ratifying and confirming all that each said attorney-in-fact and
agent, or their or his substitute or substitutes, may lawfully do or cause to be
done by virtue hereof. This Power of Attorney may be signed in several
counterparts.
 
     Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below by the following persons in the
capacities and on the dates indicated.
SIGNATURE                                      TITLE                             DATE
------------------------------------------  -------------------------------------------   -------------------
/s/ STEVEN GIRGENTI              Chairman of the Board and Chief Executive         August 29, 1997
------------------------------------------  Officer (principal executive officer)
             Steven Girgenti
 
            /s/ STUART DIAMOND              Executive Vice President, Chief Financial         August 29, 1997
------------------------------------------  Officer and Secretary (principal financial
              Stuart Diamond                and accounting officer)
 
        /s/ WILLIAM LESLIE MILTON           Vice Chairman of the Board and President          August 29, 1997
------------------------------------------
          William Leslie Milton
 
            /s/ FRANCIS HUGHES              Director                                          August 29, 1997
------------------------------------------
              Francis Hughes
II-5