SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                                    FORM 8-K

                                 CURRENT REPORT

                     PURSUANT TO SECTION 13 OR 15(d) OF THE

                         SECURITIES EXCHANGE ACT OF 1934

        Date of report (Date of earliest event reported) March 23, 1998

                            WALSH INTERNATIONAL INC.
               (Exact Name of Registrant as Specified in Charter)

         Delaware                       0-28202                   51-0309207
(State or Other Jurisdiction          (Commission             (I.R.S. Employer

      of Incorporation)               File Number)           Identification No.)

105 Terry Drive, Suite 118, Newtown, Pennsylvania                  18940
    (Address of Principal Executive Offices)                    (Zip Code)

Registrant's telephone number, including area code  (215)860-4949

--------------------------------------------------------------------------------
          (Former Name or Former Address, if Changed Since Last Report)

<PAGE>

Item 5.  Other Events.

     On March 23, 1998, the registrant, Walsh International Inc. (the "Company")
entered into an  Agreement  and Plan of Merger (the  "Merger  Agreement")  among
Cognizant  Corporation  ("Cognizant"),  WAC Inc., a  wholly-owned  subsidiary of
Cognizant ("Acquisition Sub") and the Company. Upon the terms and subject to the
conditions  contained in the Merger Agreement,  Acquisition Sub shall merge with
and into the Company with the Company surviving as a wholly-owned  subsidiary of
Cognizant (the "Merger"). Pursuant to the Merger Agreement, each share of common
stock,  $.01 par value,  of the  Company  ("Company  Common  Stock")  issued and
outstanding at the effective time of the Merger (the "Effective  Time") shall be
converted as discussed below.

      On January 15, 1998,  Cognizant announced a planned spin-off  distribution
(the  "Cognizant  Distribution")  that  will  result  in the  reorganization  of
Cognizant into two separate publicly traded companies:  IMS Health  Incorporated
("IMS") and Nielsen Media  Research,  Inc. If the Effective Time occurs prior to
the record date for the Cognizant Distribution then each share of Company Common
Stock issued and  outstanding  at the Effective  Time will be converted into the
right to receive a fraction of a share of  Cognizant's  common  stock,  $.01 par
value ("Cognizant Common Stock"). If the Effective Time occurs subsequent to the
record date for the  Cognizant  Distribution  then each share of Company  Common
Stock issued and  outstanding  at the Effective  Time will be converted into the
right to receive a fraction  of a share of IMS's  common  stock,  $.01 par value
("IMS Common Stock").  The exchange ratio  applicable to Cognizant  Common Stock
will be  determined  by  reference to the average of the closing sale prices per
share  of  Cognizant  Common  Stock  on the New York  Stock  Exchange  Composite
Transactions  Tape  on  each  of the 15  consecutive  trading  days  immediately
preceding the second trading day prior to the Effective Time. The exchange ratio
applicable  to the IMS  Common  Stock will be  determined  by  reference  to the
average of the closing sale prices per share of IMS Common Stock on the New York
Stock Exchange Composite Transactions Tape on each of the 10 consecutive trading
days  immediately  preceding the second trading day prior to the Effective Time.
If the  Effective  Time had occurred on the date of the Merger  Agreement,  each
share of  Company  Common  Stock  would  have been  converted  into the right to
receive a fraction of a share of Cognizant  Common Stock valued at $15.75 (based
on an average closing sale price for Cognizant Common Stock of $51.792).

     Concurrently with the execution of the Merger  Agreement,  the Company also
entered  into a Stock  Option  Agreement  (the "Stock  Option  Agreement")  with
Cognizant  pursuant  to which the  Company  granted  to  Cognizant  an option to
purchase up to an aggregate

                                       2

<PAGE>

2,111,815  shares of Company  Common  Stock at $15.75  per share.  The option is
exercisable  only  in  the  event  the  Merger  Agreement  is  terminated  under
circumstances  in which Cognizant  becomes entitled to receive a termination fee
from the Company.  In addition,  under certain  circumstances,  the Stock Option
Agreement  entitles  Cognizant to require the Company to  repurchase  the option
and/or any shares obtained through exercise of the option. The maximum amount of
compensation  the Company is required to pay  Cognizant  under the Stock  Option
Agreement together with any termination fees and expense  reimbursement is $5.55
million.

     In connection with its approval of the Merger and the Merger Agreement, the
Board of Directors of the Company amended the Rights Agreement of the Company to
the effect that none of the Merger,  the Merger  Agreement  or the Stock  Option
Agreement  will cause the Rights  issued  under the Rights  Agreement  to become
exercisable.

     The Merger is subject to the approval of the  stockholders  of the Company,
and to certain other  conditions.  The Merger  Agreement  (without  schedules or
exhibits) is attached hereto as Exhibit 2.1.

Item 7. Financial Statements, Pro Forma Financial Information and Exhibits.

(c)  Exhibits.

Number             Description
------             -----------

  2.1              Agreement  and Plan of  Merger,  dated as of March 23,  1998,
                   among Cognizant Corporation, WAC Inc. and Walsh International
                   Inc.

  2.2              Stock Option Agreement, dated as of March 23, 1998, by and
                   between Walsh International Inc. and Cognizant Corporation.

 99.1              Press Release dated March 23, 1998.

 99.2              Press Release dated March 23, 1998.


                                       3

<PAGE>

                                   SIGNATURES

     Pursuant to the  requirements  of the Securities  Exchange Act of 1934, the
Company  has  duly  caused  this  report  to be  signed  on  its  behalf  by the
undersigned, thereunto duly authorized.

                                            WALSH INTERNATIONAL INC.

                                            By: /s/ MARTYN WILLIAMS

                                                --------------------------------
                                                Name: Martyn Williams
                                                Title: Chief Financial Officer

Date:  April 1, 1998

                                       4

<PAGE>

                                INDEX TO EXHIBITS

Exhibit       Description                                           

  2.1         Agreement and Plan of Merger dated as of March 23,
              1998 among Cognizant Corporation, WAC Inc. and
              Walsh International Inc.

  2.2         Stock Option Agreement, dated as of March 23, 1998,
              by and between Walsh International Inc. and
              Cognizant Corporation.

 99.1         Press Release dated March 23, 1998.

 99.2         Press Release dated March 23, 1998.
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SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549

                                    FORM 8-K

                                 CURRENT REPORT

                     PURSUANT TO SECTION 13 OR 15(d) OF THE

                         SECURITIES EXCHANGE ACT OF 1934

        Date of report (Date of earliest event reported) March 23, 1998

                            WALSH INTERNATIONAL INC.
               (Exact Name of Registrant as Specified in Charter)

         Delaware                       0-28202                   51-0309207
(State or Other Jurisdiction          (Commission             (I.R.S. Employer

      of Incorporation)               File Number)           Identification No.)

105 Terry Drive, Suite 118, Newtown, Pennsylvania                  18940
    (Address of Principal Executive Offices)                    (Zip Code)

Registrant's telephone number, including area code  (215)860-4949

--------------------------------------------------------------------------------
          (Former Name or Former Address, if Changed Since Last Report)
Item 5.  Other Events.

     On March 23, 1998, the registrant, Walsh International Inc. (the "Company")
entered into an  Agreement  and Plan of Merger (the  "Merger  Agreement")  among
Cognizant  Corporation  ("Cognizant"),  WAC Inc., a  wholly-owned  subsidiary of
Cognizant ("Acquisition Sub") and the Company. Upon the terms and subject to the
conditions  contained in the Merger Agreement,  Acquisition Sub shall merge with
and into the Company with the Company surviving as a wholly-owned  subsidiary of
Cognizant (the "Merger"). Pursuant to the Merger Agreement, each share of common
stock,  $.01 par value,  of the  Company  ("Company  Common  Stock")  issued and
outstanding at the effective time of the Merger (the "Effective  Time") shall be
converted as discussed below.

      On January 15, 1998,  Cognizant announced a planned spin-off  distribution
(the  "Cognizant  Distribution")  that  will  result  in the  reorganization  of
Cognizant into two separate publicly traded companies:  IMS Health  Incorporated
("IMS") and Nielsen Media  Research,  Inc. If the Effective Time occurs prior to
the record date for the Cognizant Distribution then each share of Company Common
Stock issued and  outstanding  at the Effective  Time will be converted into the
right to receive a fraction of a share of  Cognizant's  common  stock,  $.01 par
value ("Cognizant Common Stock"). If the Effective Time occurs subsequent to the
record date for the  Cognizant  Distribution  then each share of Company  Common
Stock issued and  outstanding  at the Effective  Time will be converted into the
right to receive a fraction  of a share of IMS's  common  stock,  $.01 par value
("IMS Common Stock").  The exchange ratio  applicable to Cognizant  Common Stock
will be  determined  by  reference to the average of the closing sale prices per
share  of  Cognizant  Common  Stock  on the New York  Stock  Exchange  Composite
Transactions  Tape  on  each  of the 15  consecutive  trading  days  immediately
preceding the second trading day prior to the Effective Time. The exchange ratio
applicable  to the IMS  Common  Stock will be  determined  by  reference  to the
average of the closing sale prices per share of IMS Common Stock on the New York
Stock Exchange Composite Transactions Tape on each of the 10 consecutive trading
days  immediately  preceding the second trading day prior to the Effective Time.
If the  Effective  Time had occurred on the date of the Merger  Agreement,  each
share of  Company  Common  Stock  would  have been  converted  into the right to
receive a fraction of a share of Cognizant  Common Stock valued at $15.75 (based
on an average closing sale price for Cognizant Common Stock of $51.792).

     Concurrently with the execution of the Merger  Agreement,  the Company also
entered  into a Stock  Option  Agreement  (the "Stock  Option  Agreement")  with
Cognizant  pursuant  to which the  Company  granted  to  Cognizant  an option to
purchase up to an aggregate

                                       2
2,111,815  shares of Company  Common  Stock at $15.75  per share.  The option is
exercisable  only  in  the  event  the  Merger  Agreement  is  terminated  under
circumstances  in which Cognizant  becomes entitled to receive a termination fee
from the Company.  In addition,  under certain  circumstances,  the Stock Option
Agreement  entitles  Cognizant to require the Company to  repurchase  the option
and/or any shares obtained through exercise of the option. The maximum amount of
compensation  the Company is required to pay  Cognizant  under the Stock  Option
Agreement together with any termination fees and expense  reimbursement is $5.55
million.

     In connection with its approval of the Merger and the Merger Agreement, the
Board of Directors of the Company amended the Rights Agreement of the Company to
the effect that none of the Merger,  the Merger  Agreement  or the Stock  Option
Agreement  will cause the Rights  issued  under the Rights  Agreement  to become
exercisable.

     The Merger is subject to the approval of the  stockholders  of the Company,
and to certain other  conditions.  The Merger  Agreement  (without  schedules or
exhibits) is attached hereto as Exhibit 2.1.

Item 7. Financial Statements, Pro Forma Financial Information and Exhibits.

(c)  Exhibits.

Number             Description
------             -----------

  2.1              Agreement  and Plan of  Merger,  dated as of March 23,  1998,
                   among Cognizant Corporation, WAC Inc. and Walsh International
                   Inc.

  2.2              Stock Option Agreement, dated as of March 23, 1998, by and
                   between Walsh International Inc. and Cognizant Corporation.

 99.1              Press Release dated March 23, 1998.

 99.2              Press Release dated March 23, 1998.

                                       3
SIGNATURES

     Pursuant to the  requirements  of the Securities  Exchange Act of 1934, the
Company  has  duly  caused  this  report  to be  signed  on  its  behalf  by the
undersigned, thereunto duly authorized.

                                            WALSH INTERNATIONAL INC.

                                            By: /s/ MARTYN WILLIAMS

                                                --------------------------------
                                                Name: Martyn Williams
                                                Title: Chief Financial Officer

Date:  April 1, 1998

                                       4
INDEX TO EXHIBITS

Exhibit       Description                                           

  2.1         Agreement and Plan of Merger dated as of March 23,
              1998 among Cognizant Corporation, WAC Inc. and
              Walsh International Inc.

  2.2         Stock Option Agreement, dated as of March 23, 1998,
              by and between Walsh International Inc. and
              Cognizant Corporation.

 99.1         Press Release dated March 23, 1998.

 99.2         Press Release dated March 23, 1998.