<PAGE>
 
     As filed with the Securities and Exchange Commission on April 6, 1999

                                                Registration No. 333-___________

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON D.C. 20549
                ________________________________________________
                                    FORM S-8
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                ________________________________________________
                      ADELPHIA COMMUNICATIONS CORPORATION

           Delaware                         4841                 23-2417713
  (State or jurisdiction of     (Primary Standard Industrial  (I.R.S. Employer
incorporation or organization)  Classification Code Number)  Identification No.)

                              Main at Water Street
                        Coudersport, Pennsylvania 16915
                    (Address of principal executive offices)
                  ___________________________________________
                      ADELPHIA COMMUNICATIONS CORPORATION
                   1998 LONG-TERM INCENTIVE COMPENSATION PLAN
                            (Full title of the plan)
                  ___________________________________________
<TABLE>
<S>                                                        <C>
       Colin H. Higgin, Esquire                                  Copies of communications to:
        Deputy General Counsel                                Carl E. Rothenberger, Jr., Esquire
  Adelphia Communications Corporation                      Buchanan Ingersoll Professional Corporation
         Main at Water Street                                          One Oxford Centre
    Coudersport, Pennsylvania 16915                              301 Grant Street, 21st Floor
(Name and address of agent for service)                            Pittsburgh, PA 15219-1410
            (814) 274-9830                                              (412) 562-8826
(Telephone number of agent for service)
</TABLE>
                                        
<TABLE>
<CAPTION>
===================================================================================================================================
                                                       CALCULATION OF REGISTRATION FEE
===================================================================================================================================
                                                                Proposed Maximum         Proposed Maximum
                                         Amount to Be          Offering Price Per       Aggregate Offering           Amount of
Title of Securities to Be Registered     Registered(1)              Share(2)                  Price              Registration Fee(3)

------------------------------------------------------------------------------------------------------------------------------------

<S>                                      <C>                   <C>                      <C>                      <C>
Class A Common Stock                        3,500,000                $61.50                $215,250,000              $59,839.50 
(par value $.01 per share)
------------------------------------------------------------------------------------------------------------------------------------

Total                                       3,500,000                $61.50                $215,250,000              $59,839.50
------------------------------------------------------------------------------------------------------------------------------------

</TABLE>
(1) The provisions of Rule 416 of the Securities Act of 1933, as amended (the
    "Securities Act") shall apply to the number of shares registered on this
    Registration Statement and shall automatically increase or decrease as a
    result of stock splits, stock dividends or similar transactions.

(2) Estimated solely for purposes of calculating the registration fee pursuant
    to Rule 457(h) of the Securities Act. In accordance with Rule 457(h) of the
    Securities Act, such price is the average of the high and low sale prices
    for the Common Stock as quoted on the Nasdaq National Market on March 29,
    1999.

(3) Calculated pursuant to Section 6(B) of the Securities Act.
<PAGE>
 
3,500,000 shares
ADELPHIA COMMUNICATIONS CORPORATION
Class A common stock


<TABLE>
<S>                                     <C>
The stockholders of Adelphia            preferential rights with respect to
Communications Corporation as           cash dividends and distributions upon
described in the caption "Selling       the liquidation of Adelphia.  Holders
Stockholders" on page 15 of this        of Class B common stock are entitled
prospectus are offering and selling     to greater voting rights than the
up to 3,500,000 shares of Adelphia's    holders of Class A common stock;
Class A common stock under this         however, the holders of Class A
prospectus.                             common stock, voting as a separate
                                        class, are entitled to elect one of
The Class A common stock is listed on   Adelphia's directors.
the Nasdaq National Market.  The      
Class A common stock's ticker symbol    You should carefully review "Risk
is "ADLAC."  On April 1, 1999, the      Factors" beginning on page 6 for a
closing sale price on the Nasdaq        discussion of things you should
National Market of a single share of    consider when investing in Class A
the Class A common stock was $63.25.    common stock.
 
Our common stock also includes Class    Neither the SEC nor any state
B common stock.  The rights of          securities commission has approved or
holders of the Class A common stock     disapproved of these securities or
and Class B common stock differ with    passed upon the adequacy or accuracy
respect to certain aspects of           of this prospectus.  Any
dividends, liquidations and voting.     representation to the contrary is a
The Class A common stock has            criminal offense.
</TABLE>


                 The date of this prospectus is April 6, 1999.

                                       2
<PAGE>
 
                               TABLE OF CONTENTS

                                                                            Page
                                                                            ----
Adelphia...................................................................   4
Risk Factors...............................................................   6
Dilution...................................................................  15
Selling Stockholders.......................................................  15
Use of Proceeds............................................................  15
Plan of Distribution.......................................................  15
Where You Can Find More Information........................................  16
Indemnification............................................................  19
Experts....................................................................  19

                                       3
<PAGE>
 
                                     ADELPHIA

  Adelphia is a leader in the telecommunications industry with cable television
and local telephone operations.  Our operations consist of providing
telecommunications services primarily over our networks, which are commonly
referred to as broadband networks because they transmit large quantities of
voice, video and data by way of digital or analog signals.  As of December 31,
1998, we owned or managed cable television systems with broadband networks that
passed in front of 3,252,830 homes and served 2,304,325 basic subscribers.  John
J. Rigas, the Chairman, President, Chief Executive Officer and founder of
Adelphia, has owned and operated cable television systems since 1952.

  We own cable systems in twelve states which are organized into seven regional
clusters: Western New York, Virginia, Western Pennsylvania, New England, Eastern
Pennsylvania, Ohio and New Jersey. These systems are located primarily in
suburban areas of large and medium-sized cities within the 50 largest television
markets. As of December 31, 1998, the broadband networks for these systems
passed in front of 2,131,978 homes and served 1,528,307 basic subscribers.

  We also provide management and consulting services to other partnerships and
corporations engaged in the ownership and operation of cable television systems.
John J. Rigas and members of his immediate family, including entities they own
or control, have substantial ownership interests in these partnerships and
corporations. As of December 31, 1998, the broadband networks for cable systems
owned by these Rigas family partnerships and corporations passed in front of
177,250 homes and served 134,443 basic subscribers.

  We also own a 50% voting interest and nonvoting preferred limited partnership
interests in Olympus Communications, L.P.  Olympus is a joint venture limited
partnership that operates a large cable system in Florida.  As of December
31, 1998, the broadband networks for this system passed in front of 943,602
homes and served 641,575 basic subscribers.

  Through our subsidiary, Hyperion Telecommunications, Inc., we own and operate
a large competitive local exchange carrier in the eastern United States.  This
means that Hyperion provides its customers with alternatives to the incumbent
local telephone company for local telephone and telecommunications services.
Hyperion's telephone operations are referred to as being facilities based, which
means it generally owns the local telecommunications networks and facilities it
uses to deliver these services, rather than leasing or renting the use of
another party's networks to do so.  As of December 31, 1998, Hyperion managed
and operated 22 telecommunications networks, including two under construction,
serving 46 markets.  Hyperion's Class A common stock is listed on the Nasdaq
National Market under the symbol "HYPT."

  Our executive offices are located at Main at Water Street, Coudersport,
Pennsylvania 16915, and our telephone number is (814) 274-9830.

Recent Developments

  On March 5, 1999, Adelphia announced that it had entered into a definitive
agreement to acquire Century Communications Corporation by merger.  Under the
agreement, Adelphia would acquire 100% of the outstanding common stock of
Century for an aggregate of approximately $826,000,000 in cash, 48,700,000
shares of Class A common stock and the assumption of approximately
$1,600,000,000 of debt.  This transaction is subject to shareholder approval by
Century and Adelphia and other customary closing conditions.  As of March 5,
1999, Century had approximately 1,600,000 basic subscribers after giving effect
to Century's pending joint venture with Tele-Communications, Inc.

  On March 2, 1999, Hyperion issued $300,000,000 of 12% Senior Subordinated
Notes due 2007.  An entity controlled by members of the Rigas family purchased
$100,000,000 of the $300,000,000 of Senior Subordinated Notes directly from
Hyperion at a price equal to the aggregate principal amount less the discount to
the initial purchasers.  The net proceeds of approximately $292,000,000 will be
used to fund Hyperion's acquisition of interests held by local partners in
certain of its networks, for capital expenditures and investments in its
networks, for working capital purposes and for general corporate purposes.

                                       4
<PAGE>
 
  On February 23, 1999, Adelphia announced that it had entered into a definitive
agreement to acquire FrontierVision Partners, L.P. for approximately
$2,100,000,000.  Under that agreement Adelphia would acquire 100% of
FrontierVision in exchange for approximately $550,000,000 in cash, 7,000,000
shares of Adelphia Class A common stock and the assumption of approximately
$1,110,000,000 of debt.  The transaction is subject to customary closing
conditions.  As of February 23, 1999, FrontierVision had approximately 702,000
basic subscribers.

  On January 29, 1999, Adelphia purchased from Telesat Cablevision, Inc., a
subsidiary of FPL Group, Inc., shares of Adelphia's stock owned by Telesat.
Adelphia purchased 1,091,524 shares of Class A common stock and the 20,000
shares of Series C Cumulative Convertible preferred stock which are convertible
into an additional 2,358,490 shares of Class A common stock.  These shares
represent 3,450,014 shares of common stock on a fully converted basis.  Adelphia
and Telesat also agreed to a redemption of Telesat's interests in Olympus by
July 11, 1999.  The redemption transaction is subject to applicable approvals of
third parties or governmental authorities.  The aggregate purchase price for
these transactions will be approximately $257,200,000.

  On January 21, 1999, Adelphia acquired Verto Communications, Inc.  Verto
provided cable television services to approximately 56,000 subscribers in the
greater Scranton, Pennsylvania area at the date of acquisition.  In connection
with the Verto acquisition, Adelphia issued 2,561,024 shares of its Class A
common stock to the former owners of Verto.

  On January 14, 1999, Adelphia completed offerings totaling 8,600,000 shares of
its Class A common stock.  In those offerings, Adelphia sold 4,600,000 newly
issued shares of Class A common stock to Goldman, Sachs & Co. at $43.25 per
share and it also sold 4,000,000 shares of its Class A common stock at $43.25
per share to a Rigas family partnership.  Adelphia used the proceeds of about
$372,000,000 from these offerings to repay subsidiary bank debt, which may be
reborrowed and used for general corporate purposes.

  On January 13, 1999, Adelphia completed offerings of $100,000,000 of 7 1/2%
Senior Notes due 2004 and $300,000,000 of 7 3/4% Senior Notes due 2009.  Net
proceeds from these offerings, after deducting offering expenses, were
approximately $393,700,000.  Of this amount, Adelphia used approximately
$160,000,000 to redeem a portion of its 9 1/2% Senior Pay-In-Kind Notes due
2004.  Adelphia used the remainder to repay borrowings under revolving credit
facilities of its subsidiaries which may be reborrowed and used for general
corporate purposes.  The terms of these notes are similar to those of Adelphia's
existing publicly held senior debt.

  On December 30, 1998, Adelphia's 66.7% owned joint venture limited partnership
with Tele-Communications, Inc., which has operations in the Western New York
region, completed a $700,000,000, eight and one-half year credit facility.  The
credit facility consists of a $350,000,000 reducing revolving credit portion and
a $350,000,000 term loan portion.  The partnership used proceeds from initial
borrowings to repay indebtedness owed to Adelphia.

                                       5
<PAGE>
 
                                  RISK FACTORS

   Before you invest in Adelphia's Class A common stock, you should be aware
that there are various risks, including those described below. You should
consider carefully these risk factors together with all of the other information
included in this prospectus before you decide to purchase any shares of
Adelphia's Class A common stock.

<TABLE>
<S>                       <C>
High Level Of                Adelphia has a substantial amount of debt.  We borrowed this money to
Indebtedness              purchase and to expand our cable systems and other operations and, to a
-------------             lesser extent, for investments and loans to our affiliates.  At December
As of December 31,        31, 1998, our indebtedness totaled approximately $3,527,452,000.  This
1998, we owe              included approximately:
approximately $3.5        .  $1,810,212,000 of Adelphia Parent Company public debt.  When we use
billion.  Our high           the term "Adelphia Parent Company" in this prospectus, we are referring
level of                     only to Adelphia Communications Corporation as a parent holding company
indebtedness can             entity, and not to its subsidiaries;
have important            .  $1,246,456,000 of debt owed by our subsidiaries to banks, other
adverse consequences         financial institutions and other persons; and
to us and to you.         .  $470,784,000 of public debt owed by Hyperion.
 
 
Debt service consumes a      Our high level of indebtedness can have important adverse consequences to
substantial portion of    us and to you.  It requires that we spend a substantial portion of the
the cash we generate.     cash we get from our business to repay the principal and interest on
This could affect our     these debts.  Otherwise, we could use these funds for general corporate
ability to invest in      purposes or for capital improvements.  Our ability to obtain new loans
our business in the       for working capital, capital expenditures, acquisitions or capital
future as well as to      improvements may be limited by our current level of debt.  In addition,
react to changes in       having such a high level of debt could limit our ability to react to
our industry or           changes in our industry and to economic conditions generally.  In
economic downturns.       addition to our debt, at December 31, 1998, the Adelphia Parent Company
                          also had approximately $148,191,000 and Hyperion had approximately
                          $228,674,000 of redeemable exchangeable preferred stock which contain
                          payment obligations that are similar to our debt obligations in these
                          respects.  Olympus also has a substantial amount of debt.

Approximately 32% of         Our debt comes due at various times up to the year 2009, including an
this debt must be paid    aggregate of approximately $1,126,169,000 which, as of December 31, 1998,
by April 1, 2003 and      we must pay by April 1, 2003.
all of it must be paid    
by 2009.                  

Our Business Requires        Our business requires substantial additional financing on a continuing
Substantial Additional    basis for capital expenditures and other purposes including:
Financing And If We Do    .  constructing and upgrading our plant and networks--some of these
Not Obtain That              upgrades we must make to comply with the requirements of local cable
Financing We May Not         franchise authorities,
Be Able To Upgrade Our    .  offering new services,
Plant, Offer Services,    .  scheduled principal and interest payments,
Make Payments When Due    .  refinancing existing debt, and
Or Refinance Existing     .  acquisitions and investments.
Debt                      
----------------------
</TABLE> 

                                       6
<PAGE>
 
<TABLE>
<S>                       <C>
                             There can be no guarantee that we will be able to issue additional debt
                          or sell stock or other additional equity on satisfactory terms, or at
                          all, to meet our future financing needs.

We Have Had Large            The Total Convertible Preferred Stock, Common Stock and Other
Losses And Negative       Stockholders' Equity (Deficiency) at December 31, 1998 was a deficit of
Stockholders' Equity      approximately $1,021,746,000.  Our continuing net losses, which are
And We Expect This To     mainly due to our high levels of depreciation and amortization and
Continue                  interest expense, have created this deficiency.  Our recent net losses
---------------------     applicable to our common stockholders were approximately as follows for
                          the periods specified:
                          .  fiscal year ended March 31, 1996 - $119,894,000;
                          .  fiscal year ended March 31, 1997 - $130,642,000;
                          .  fiscal year ended March 31, 1998 - $192,729,000; and
                          .  nine months ended December 31, 1998 - $135,848,000.

                             We expect to continue to incur large net losses for the next several
                          years.

Our earnings have been       Our earnings could not pay for our combined fixed charges and preferred
insufficient to pay       stock dividends during these periods by the amounts set forth in the
for our fixed charges     table below, although combined fixed charges and preferred stock
and preferred stock       dividends included substantial non-cash charges for depreciation,
dividends.                amortization and non-cash interest expense on some of our debts and the
                          non-cash expense of Hyperion's preferred stock dividends:

                                                                     Earnings          Non-Cash
                                                                    Deficiency          Charges
                                                                  ---------------  -----------------
                          .  fiscal year ended March 31, 1996        $ 78,189,000       $127,319,000
                          .  fiscal year ended March 31, 1997        $ 61,848,000       $165,426,000
                          .  fiscal year ended March 31, 1998        $113,941,000       $195,153,000
                          .  nine months ended December 31, 1998     $116,899,000       $186,022,000
</TABLE> 

                                       7
<PAGE>
 
<TABLE>
<S>                       <C>
If we could not              Historically, the cash we generate from our operating activities and
refinance our debt or     borrowings has been sufficient to meet our requirements for debt service,
obtain new loans, we      working capital, capital expenditures, and investments in and advances to
would likely have to      our affiliates, and we have depended on getting additional borrowings to
consider various          meet our liquidity requirements.  Although in the past we have been able
options such as the       both to refinance our debt and to obtain new debt, there can be no
sale of additional        guarantee that we will be able to continue to do so in the future or that
equity or some of our     the cost to us or the other terms which would affect us would be as
assets to meet the        favorable to us as our current loans and credit agreements.  We believe
principal and interest    that our business will continue to generate cash and that we will be able
payments we owe,          to obtain new loans to meet our cash needs.  However, the covenants in
negotiate with our        the indentures and credit agreements for our current debt limit our
lenders to restructure    ability to borrow more money.
existing loans or         
explore other options     
available under           
applicable laws           
including those under     
reorganization or         
bankruptcy laws. We       
can not guarantee that    
any options available     
to us would enable us     
to repay our debt in      
full.

Competition                  The telecommunications services provided by Adelphia are subject to
-----------               strong competition and potential competition from various sources.  Our
                          cable television systems compete with other means of distributing video
Our cable television      to home televisions such as Direct Broadcast Satellite systems, commonly
business is subject to    known as DBS systems, and Multichannel Multipoint Distribution systems.
strong competition        Some of the regional Bell telephone operating companies and other local
from several sources      telephone companies are in the process of entering the video-to-home
which could adversely     business and several have expressed their intention to enter the
affect revenue or         video-to-home business.  In addition, some regional Bell operating
revenue growth.           companies and local telephone companies have facilities which are capable
                          of delivering cable television service.  The equipment which telephone
                          companies use in providing local exchange service may give them
                          competitive advantages over us in distributing video to home televisions.
                          The regional Bell operating companies and other potential competitors
                          have much greater resources than Adelphia and would constitute formidable
                          competition for our cable television business.  We cannot predict either
                          the extent to which competition will continue to materialize or, if such
                          competition materializes, the extent of its effect on our cable
                          television business.
 
                             We also face competition from other communications and entertainment
                          media, including conventional off-air television broadcasting services,
                          newspapers, movie theaters, live sporting events and home video products.
                          We cannot predict the extent to which competition may affect us.

Hyperion's operations        In each of the markets served by Hyperion's networks, the competitive
are also subject to       local exchange carrier services offered by Hyperion compete principally
risk because Hyperion     with the services offered by the incumbent local telephone exchange
competes principally      carrier company serving that area.  Local telephone companies have
with established local    long-standing relationships with their customers, have the potential to
telephone carriers        subsidize competitive services from monopoly service revenues, and
that have                 benefit from favorable state and federal regulations.  The merger of Bell Atlantic 
long-standing
</TABLE> 

                                       8
<PAGE>
 
<TABLE>
<S>                       <C>
utility                   and NYNEX created a very large company whose combined territory
relationships with        covers a substantial portion of Hyperion's markets.  Other combinations
their customers and       are occurring in the industry, which may have a material adverse effect
pricing flexibility       on Hyperion and us.
for local telephone       
services.                 
                             We think that local telephone companies will gain increased pricing
                          flexibility from regulators as competition increases.  Hyperion's
                          operating results and cash flow could be materially and adversely
                          affected by actions by regulators, including permitting the incumbent
                          local telephone companies in Hyperion's markets to do the following:
                          .  lower their rates substantially;
                          .  engage in aggressive volume and term discount pricing practices for
                             their customers; or
                          .  charge excessive fees to Hyperion for interconnection to the incumbent
                             local telephone company's networks.

If the regional Bell         The regional Bell operating companies can now obtain regulatory approval
telephone companies       to offer long distance services if they comply with the interconnection
could get regulatory      requirements of the federal Telecommunications Act of 1996.  To date, the
approval to offer long    FCC has denied the requests for approval filed by regional Bell operating
distance service in       companies in Hyperion's operating areas.  However, an approval of such a
competition with          request could result in decreased market share for the major long
Hyperion's significant    distance carriers which are among Hyperion's significant customers.  This
customers, some of        could have a material adverse effect on Hyperion.
Hyperion's major          
customers could lose      
market share.             

The regional Bell            Regional Bell operating companies have also recently filed petitions with
telephone companies       the FCC requesting waivers of other obligations under the
continue to seek other    Telecommunications Act of 1996.  These involve services the Company also
regulatory approvals      provides such as high speed data, long distance, and services to Internet
that could                Service Providers.  If the FCC grants the regional Bell operating
significantly enhance     companies' petitions, this could have a material adverse effect on
their competitive         Hyperion.
position against          
Hyperion.                 

Potential competitors        Potential competitors for Hyperion include other competitive local
to Hyperion's             exchange carriers, incumbent local telephone companies which are not
telecommunications        subject to regional Bell operating companies' restrictions on offering
services include the      long distance service, AT&T, MCIWorldCom, Sprint and other long distance
regional Bell             carriers, cable television companies, electric utilities, microwave
telephone companies,      carriers, wireless telecommunications providers and private networks
AT&T, MCIWorldCom and     built by large end users.  Both AT&T and MCIWorldCom have announced that
Sprint, electric          they have begun to offer local telephone services in some areas of the
utilities and other       country, and AT&T recently announced a new wireless technology for
companies that have       providing local telephone service.  AT&T and Tele-Communications, Inc.
advantages over           have merged.  Although Hyperion has good relationships with the long
Hyperion.                 distance carriers, they could build their own facilities, purchase other
                          carriers or their facilities, or resell the services of other carriers
                          rather than use Hyperion's services when entering the market for local
                          exchange services.
</TABLE> 

                                       9
<PAGE>
 
<TABLE>
<S>                       <C>
                             Many of Hyperion's current and potential competitors, particularly
                          incumbent local telephone companies, have financial, personnel and other
                          resources substantially greater than those of Hyperion, as well as other
                          competitive advantages over Hyperion.

We Are Subject To            The cable television industry and the provision of local telephone
Extensive Regulation      exchange services are subject to extensive regulation at the federal,
--------------------      state and local levels, and many aspects of such regulation are currently
                          the subject of judicial proceedings and administrative or legislative
Our cable television      proposals.  In particular, the FCC adopted regulations that limit our
and telecommunications    ability to set and increase rates for our basic and cable programming
businesses are heavily    service packages and for the provision of cable television-related
regulated as to rates     equipment.  The law permits certified local franchising authorities to
we can charge and         order refunds of rates paid in the previous twelve-month period
other matters.  This      determined to be in excess of the permitted reasonable rates.  It is
regulation could limit    possible that rate reductions or refunds of previously collected fees may
our ability to            be required in the future.
increase rates, cause                                                                               
us to decrease then          The cable television industry is subject to state and local regulations
current rates or          and we must comply with rules of the local franchising authorities to     
require us to refund      retain and renew our cable franchises, among other matters.  There can be 
previously collected      no assurances that the franchising authorities will not impose new and    
fees.                     more restrictive requirements as a condition to franchise renewal.        

The federal                  The federal Telecommunications Act of 1996 substantially changed federal,
Telecom-munications       state and local laws and regulations governing our cable television and
Act of 1996 may have a    telecommunications businesses.  This law could materially affect the
significant impact on     growth and operation of the cable television industry and the cable
our cable television      services we provide.  Although this legislation may lessen regulatory
and telephone             burdens, the cable television industry may be subject to new competition
businesses.               as a result.  There are numerous rulemakings that have been and continue
                          to be undertaken by the FCC which will interpret and implement the
                          provisions of this law.  Furthermore, portions of this law have been, and
                          likely other portions will be, challenged in the courts.  We cannot
                          predict the outcome of such rulemakings or lawsuits or the short- and
                          long-term effect, financial or otherwise, of this law and FCC rulemakings
                          on us.

                             Similarly, the Telecommunications Act of 1996 removes entry barriers for
                          all companies and could increase substantially the number of competitors
                          offering comparable services in Hyperion's markets or potential markets.
                          Furthermore, we cannot guarantee that rules adopted by the FCC or state
                          regulators or other legislative or judicial initiatives relating to the
                          telecommunications industry will not have a material adverse effect on
                          Hyperion.

Unequal Voting Rights        Adelphia has two classes of common stock -- Class A which carries one
Of Stockholders           vote per share and Class B which carries ten votes per share.  The shares
---------------------     being offered to you by this prospectus are Class A shares.  Under our
                          Certificate of Incorporation, the Class A shares elect only one of our
                          eight directors.
</TABLE> 

                                       10

<PAGE>
 
<TABLE>
<S>                       <C>
Control Of Voting Power      As of March 1, 1999, the Rigas family beneficially owned shares
By The Rigas Family       representing about 48% of the total number of outstanding shares of both
-----------------------   classes of Adelphia's common stock and about 81% of the total voting
                          power of Adelphia's shares.  The public holds a majority of the
The Rigas family can      outstanding Class A shares, although the Rigas family also owns about 36%
control stockholder       of those shares as of March 1, 1999.  The Rigas family owns about 99% of
decisions on very         Adelphia's Class B shares.  The Rigas family also owns shares of
important matters.        Adelphia's 8% Series C Cumulative Convertible preferred stock which, if
                          converted, would increase its voting power and beneficial ownership.  As
                          a result of the Rigas family's stock ownership and an agreement among the
                          Class B stockholders, members of the Rigas family have the power to elect
                          seven of eight Adelphia directors, and if they converted their
                          Convertible preferred stock might be able to elect all eight directors.
                          In addition, the Rigas family could control stockholder decisions on
                          other matters such as amendments to our Certificate of Incorporation and
                          Bylaws, and mergers or other fundamental corporate transactions.
 
There Are Potential          John J. Rigas and the other executive officers of Adelphia, including
Conflicts Of Interest     other members of the Rigas family, own other corporations and
Between Adelphia And      partnerships, which are managed by us for a fee.  Subject to the
The Rigas Family          restrictions contained in a business opportunity agreement regarding
---------------------     future acquisitions, Rigas family members and the executive officers are
                          free to continue to own these interests and acquire additional interests
                          in cable television systems.  These activities could present a conflict
                          of interest with us, such as how much time our executive officers devote
                          to our business.  In addition, there have been and will continue to be
                          transactions between us and the executive officers or the other entities
                          they own or have affiliations with.  Our public debt indentures contain
                          covenants that place some restrictions on transactions between us and our
                          affiliates.

Holding Company              The Adelphia Parent Company directly owns no significant assets other
Structure And             than stock, partnership interests, equity and other interests in our
Potential Impact Of       subsidiaries and in other companies.  This creates risks regarding our
Restrictive Covenants     ability to provide cash to the Adelphia Parent Company to repay the
In Subsidiary Debt        interest and principal which it owes, our ability to pay cash dividends
Agreements                to our common stockholders in the future, and the ability of our
---------------------     subsidiaries and other companies to respond to changing business and
                          economic conditions and to get new loans.

The Adelphia Parent          The public indentures, and the credit agreements for bank and other
Company depends on its    financial institution loans, of our subsidiaries and other companies
subsidiaries and other    restrict their ability and the ability of the companies they own to make
companies in which it     payments to the Adelphia Parent Company.  These agreements also place
has investments, to       other restrictions on the borrower's ability to borrow new funds and
fund its cash needs.      include requirements for the borrowers to remain in compliance with the
                          loans.  The ability of a subsidiary or a company in which we have
                          invested to comply with debt restrictions may be affected by events that
                          are beyond our control.  The breach of any of these covenants could
                          result in a default which could result in all loans and other amounts
                          owed to its lenders, to be due and payable.  Our subsidiaries and
                          companies in which we have invested might not be able to repay in full
                          the accelerated loans.
</TABLE> 

                                       11
<PAGE>
 
<TABLE>
<S>                       <C>
It Is Unlikely You Will      Adelphia has never declared or paid cash dividends on any of its common
Receive A Return On       stock and has no intention of doing so in the foreseeable future.  As a
Your Shares Through       result, it is unlikely that you will receive a return on your shares
The Payment Of Cash       through the payment of cash dividends.
Dividends                 
-----------------------

Future Sales Of              Sales of a substantial number of shares of Class A common stock or Class
Outstanding Common        B common stock, including sales by any pledgees of such shares, could
Stock Could Adversely     adversely affect the market price of our Class A common stock and could
Affect The Market         impair our ability in the future to raise capital through stock offerings.
Price Of Our Common                                                                                     
Stock                        Under various registration rights agreements or arrangements, as of           
---------------------     January 26, 1999, the Rigas family has the right, subject to some             
                          limitations, to require Adelphia to register substantially all of the         
                          shares which it owns of the Class A common stock--15,029,119 shares,          
                          Class B common stock--10,736,544 shares and the equivalent number of          
                          shares of Class A common stock into which they may be converted, and          
                          Convertible preferred stock--80,000 shares and the 9,433,962 shares of        
                          Class A common stock into which they may be converted.  Among others,         
                          Adelphia has registered or agreed to register for public sale the             
                          following shares:                                                             
                          .  for the Rigas family -- up to 11,000,000 shares of Class A common
                             stock, 80,000 shares of Convertible preferred stock and the Class A
                             common stock issuable upon conversion of the Convertible preferred stock;
                          .  for Booth American Company -- 3,571,428 shares of Class A common stock
                             owned as of March 24, 1998;
                          .  for the selling stockholders receiving shares in the Verto acquisition
                             -- 2,561,024 shares of Class A common stock;
                          .  in connection with the January 14, 1999 equity offerings 4,000,000
                             shares of Class A common stock purchased by a Rigas family partnership;
                          .  in connection with the pending FrontierVision acquisition described in
                             Recent Developments, Adelphia has agreed to register 7,000,000 shares of
                             Class A common stock which Adelphia will issue at closing.  Adelphia will
                             also register 1,000,000 shares issued in connection with the
                             FrontierVision purchase agreement and the escrow arrangement under that
                             agreement for the benefit of the owners of  FrontierVision in the event
                             that transaction does not close; and
                          .  in connection with the pending Century acquisition described in Recent
                             Developments, Adelphia expects to register approximately 48,700,000 shares
                             of Class A common stock.

                             Approximately 14,904,000 shares of Class A common stock and up to 80,000
                          shares of Convertible preferred stock, including the underlying Class A
                          common stock, have been pledged in connection with margin loans made to
                          members of the Rigas family.  These pledgees could freely sell any shares
                          acquired upon a foreclosure.

Purchasers Of Our            Persons purchasing Class A common stock will incur immediate and
Common Stock Will         substantial net tangible book value dilution.
Incur Immediate           
Dilution                  
-----------------
</TABLE> 

                                       12
<PAGE>
 
<TABLE>
<S>                       <C>
Adelphia's Acquisitions      Because Adelphia is experiencing a period of rapid expansion through
And Expansion Could       acquisition, the operating complexity of Adelphia, as well as the
Involve Operational       responsibilities of management personnel, have increased.  Adelphia's
Risks                     ability to manage such expansion effectively will require it to continue
-----------------------   to expand and improve its operational and financial systems and to
                          expand, train and manage its employee base.

                             Both the Century and FrontierVision transactions involve the acquisition
                          of companies that have previously operated independently.  Adelphia may
                          not be able to integrate the operations of these companies without some
                          level of difficulty, such as the loss of key personnel.  There is no
                          guarantee that Adelphia will be able to realize the benefits expected
                          from the integration of operations from these transactions.

The Century Acquisition      The Century merger requires approvals from Century's shareholders and
May Not Be Completed      Adelphia's stockholders. Although under the merger and related agreements
If The Required           the Class B shareholders of Century and the controlling stockholders of
Approval of Century's     Adelphia have agreed to vote in favor of the merger, the companies cannot
Class A Shareholders      predict the ultimate outcome of the required vote of the Class A
Is Not Obtained           shareholders of Century.  If that vote is not obtained, the companies
-----------------------   might not be able to complete the proposed transaction as currently
                          structured or in a timely manner, if at all.

Year 2000 Issues             The year 2000 issue refers to the inability of computerized systems and
Present Risks To Our      technologies to recognize and process dates beyond December 31, 1999.
Business Operations In    This could present risks to the operation of our business in several
Several Ways              ways.  Our computerized business applications that could be adversely
----------------------    affected by the year 2000 issue include:
                          .  information processing and financial reporting systems,
                          .  customer billing systems,
                          .  customer service systems,
                          .  telecommunication transmission and reception systems, and
                          .  facility systems.

                             System failure or miscalculation could result in an inability to process
                          transactions, send invoices, accept customer orders or provide customers
                          with products and services.  Although we are evaluating the impact of the
                          year 2000 issue on our business and are seeking to implement necessary
                          solutions, this process has not been completed.

                             There can be no assurance that the systems of other companies on which
                          our systems rely will be year 2000 ready or timely converted into systems
                          compatible with our systems.  Our failure or a third-party's failure to
                          become year 2000 ready, or our inability to become compatible with third
                          parties with which we have a material relationship, may have a material
                          adverse effect on us, including significant service interruption or
                          outages; however, we cannot currently estimate the extent of any such
                          adverse effects.

Forward-Looking              The statements contained or incorporated by reference in this prospectus
Statements In This        that are not historical facts are "forward-looking statements" and can be
Prospectus Are Subject    identified by the use of forward-looking terminology such as "believes,"
To Risks And              "expects," "may," "will," "should," "intends" or "anticipates" or the
Uncertainties             negative thereof or other variations thereon or comparable terminology,
----------------------    or by discussions of strategy that involve risks and uncertainties.
</TABLE> 

                                       13
<PAGE>
 
<TABLE>
<S>                       <C>
                             Certain information set forth or incorporated by reference in this
                          prospectus, including "Management's Discussion and Analysis of Financial
                          Condition and Results of Operations" in Adelphia's 1998 Annual Report on
                          Form 10-K and in Adelphia's Form 10-Qs, is forward-looking, such as
                          information relating to the effects of future regulation, future capital
                          commitments and the effects of competition.  Such forward-looking
                          information involves important risks and uncertainties that could
                          significantly affect expected results in the future from those expressed
                          in any forward-looking statements made by, or on behalf of, us.  These
                          risks and uncertainties include, but are not limited to, uncertainties
                          relating to economic conditions, acquisitions and divestitures,
                          government and regulatory policies, the pricing and availability of
                          equipment, materials, inventories and programming, technological
                          developments, year 2000 issues and changes in the competitive environment
                          in which we operate.  Persons reading this prospectus are cautioned that
                          such statements are only predictions and that actual events or results
                          may differ materially.  In evaluating such statements, readers should
                          specifically consider the various factors which could cause actual events
                          or results to differ materially from those indicated by such
                          forward-looking statements.
</TABLE>

                                       14
<PAGE>
 
                                     DILUTION

  The net tangible book value of Adelphia's common stock as of December 31, 1998
was a deficit of approximately $2,050,905,000 or negative $48.72 a share.  Net
tangible book value per share represents the amount of Adelphia's convertible
preferred stock, common stock and other stockholders' equity (deficiency), less
intangible assets, divided by shares of Adelphia's common stock outstanding.
Purchasers of Class A common stock will have an immediate dilution of net
tangible book value which, due to our having a net tangible book value deficit,
will exceed the purchase price per share.  For example, in the January 14, 1999
equity offerings, the purchase price of a single share initially sold to the
public was $45.00 and the net tangible book value dilution per share was $78.53,
based on net tangible book value as of December 31, 1998. Net tangible book
value dilution per share represents the difference between the amount per share
paid by purchasers of shares of Class A common stock in an offering by Adelphia
and the pro forma net tangible book value per share of the common stock
immediately after completion of such offering.

                               SELLING STOCKHOLDERS

  As the names and amounts of securities to be sold by selling stockholders
become known, the following information about each selling stockholder will be
included in a prospectus supplement:  the name and position(s) over the last
three years with Adelphia of each selling stockholder; the number of shares of
Class A common stock owned by each selling stockholder; the number of shares of
Class A common stock available to be acquired by each selling stockholder
pursuant to the Plan and being registered for resale by the selling
stockholders; and the number of shares of Class A common stock and the
percentage, if 1% or more, of the total class of Class A common stock
outstanding to be beneficially owned by each selling stockholder following this
offering.


                                USE OF PROCEEDS

  All net proceeds from the sale of the shares will go to the stockholders who
offer and sell them.  We will not receive any proceeds from the sale of shares
by the selling stockholders.


                              PLAN OF DISTRIBUTION

  Adelphia is registering the shares on behalf of the selling stockholders.
References in this section to selling stockholders also includes any pledgees,
donees or transferees identified in a supplement to this prospectus as described
above.  The selling stockholders may offer their shares at various times in one
or more of the following transactions:

 .  in transactions, which may involve crosses or block transactions, on any
   national securities exchange or quotation service on which the shares may be
   listed or quoted at the time of sale;

 .  in the over-the-counter market;

 .  in private transactions other than in the over-the-counter market or on an
   exchange;

 .  in connection with short sales of shares;

 .  by pledge to secure debts and other obligations;

 .  in connection with the writing of non-traded and exchange-traded call
   options, in hedge transactions and in settlement of other transactions in
   standardized or over-the-counter options; or

 .  in a combination of any of the above transactions.

                                       15
<PAGE>
 
  The selling stockholders may sell their shares at market prices at the time of
sale, at prices related to market prices, at negotiated prices or at fixed
prices.

  The selling stockholders may use broker-dealers to sell their shares.  If this
happens, broker-dealers will either receive discounts or commissions from the
selling stockholders, or they will receive commissions from purchasers of shares
for whom they acted as agents.  The selling stockholders, any brokers, dealers
and any other participating brokers or dealers may be deemed to be
"underwriters" within the meaning of the Securities Act in connection
with these sales, and any profits realized or commissions received may be deemed
underwriting compensation.

  The selling stockholders may also enter into hedging transactions with broker-
dealers or other financial institutions.  In connection with these transactions,
broker-dealers or other financial institutions may engage in short sales of
Adelphia's Class A common stock in the course of hedging the positions they
assume with selling stockholders.  The selling stockholders may also enter into
options or other transactions with broker-dealers or other financial
institutions which require the delivery, to that broker-dealer or other
financial institution, the shares offered under this prospectus.  The shares
that broker-dealer or other financial institution receives in those types of
transactions may be resold under this prospectus.

  Selling stockholders also may resell all or a portion of the shares in open
market transactions in reliance upon Rule 144 under the Securities Act of 1933,
provided they meet the criteria and conform to the requirements of that Rule.

  When a particular offering of shares is made, if required, we will distribute
to you a prospectus supplement.  This supplement will set forth the names of the
selling stockholders, the aggregate amount of shares being offered, the number
of such securities owned prior to and after the completion of any such offering,
and, to the extent required, the terms of the offering, including the name or
names of any underwriters, broker-dealers or agents, any discounts, commissions
and other terms constituting compensation from the selling stockholders and any
discounts, commissions or concessions allowed or reallowed or paid to broker-
dealers.

  To comply with the securities law in some jurisdictions, the shares will be
offered or sold in particular jurisdictions only through registered or licensed
brokers or dealers.  In addition, in some jurisdictions the shares may not be
offered or sold unless they have been registered or qualified for sale in that
jurisdictions or an exemption from registration or qualification is available
and is complied with.

  To comply with rules and regulations under the  Exchange Act, persons engaged
in a distribution of the shares may be limited in their ability to engage in
market activities with respect to such shares.  In addition and without limiting
the foregoing, each selling stockholder will be subject to applicable provisions
of the Exchange Act and the rules and regulations thereunder, which provisions
may limit the timing of purchases and sales of any of the shares by the selling
stockholders.  All of these things may affect the marketability of the shares.

  All expenses of the registration of the shares will be paid by Adelphia,
including, without limitation, Commission filing fees and expenses of compliance
with state securities or "blue sky" laws; provided, however, that the selling
stockholders will pay all underwriting discounts and selling commissions, if
any.  The selling stockholders and Adelphia may enter into agreements in the
future regarding contribution and indemnification for civil liabilities,
including liabilities under the Securities Act.

                      WHERE YOU CAN FIND MORE INFORMATION

  Adelphia files annual, quarterly and special reports, as well as proxy
statements and other information with the SEC.  You may read and copy any
document Adelphia files with the SEC at the SEC's Public Reference Room at 450
Fifth Street, N.W., Washington, D.C. 20549 or at its Regional Offices in
Chicago, Illinois or New York, New York.  You may obtain further information
about the operation of the Public Reference Room by calling the SEC at 1-800-
SEC-0330.  Adelphia's SEC filings are also available to the public over the
Internet at the SEC's web site at

                                       16
<PAGE>
 
http://www.sec.gov, which contains reports, proxy statements and other
information regarding registrants like Adelphia that file electronically with
the SEC.

  This prospectus is part of a registration statement on Form S-8 filed by
Adelphia with the SEC under the Securities Act.  As permitted by SEC rules, this
prospectus does not contain all of the information included in the registration
statement and the accompanying exhibits filed with the SEC.  You may refer to
the registration statement and its exhibits for more information.

  The SEC allows Adelphia to "incorporate by reference" into this prospectus the
information it files with the SEC.  This means that Adelphia can disclose
important information to you by referring you to those documents.  The
information incorporated by reference is considered to be part of this
prospectus.  If Adelphia subsequently files updating or superseding information
in a document that is incorporated by reference into this prospectus, the
subsequent information will also become part of this prospectus and will
supersede the earlier information.

  Adelphia is incorporating by reference the following documents that it has
filed with the SEC:

 .  its Annual Report on Form 10-K for the year ended March 31, 1998, which
   incorporates, in Items 7 and 8 to such Form 10-K, portions of the Form 10-K
   for the fiscal year ended December 31, 1997 of Olympus Communications, L.P.
   and Olympus Capital Corporation, as amended by Adelphia's Form 10-K/A dated
   July 27, 1998;

 .  its Quarterly Reports on Form 10-Q for the quarters ended June 30, 1998,
   September 30, 1998 and December 31, 1998;

 .  its Current Reports on Form 8-K for the events dated June 29, 1998, July 2,
   1998, August 3, 1998, August 18, 1998, September 10, 1998, November 9, 1998,
   November 12, 1998, December 23, 1998, January 11, 1999, February 22, 1999,
   February 23, 1999, and March 5, 1999;

 .  its definitive proxy statement dated September 11, 1998 with respect to the
   Annual Meeting of Stockholders held on October 6, 1998; and

 .  the description of its Class A common stock contained in:

   .  Adelphia's registration statement filed with the SEC under Section 12 of
      the Exchange Act and subsequent amendments and reports filed to update
      such description; and

   .  Adelphia's registration statement on Form S-3 (File No. 333-74219).

Adelphia is also incorporating by reference into this prospectus:

   .  all of its future filings with the SEC under Sections 13(a), 13(c), 14 or
      15(d) of the Exchange Act until this offering has been completed; and

   .  all of its filings made by it under the Exchange Act after the date the
      registration statement to which this prospectus is a part was initially
      filed and prior to the effective date of that registration statement.

  You may obtain a copy of any of our filings which are incorporated by
reference, at no cost, by writing to or telephoning us at the following address:

                    Adelphia Communications Corporation
                    Main at Water Street
                    Coudersport, Pennsylvania  16915
                    Attention:  Investor Relations
                    Telephone:  (814) 274-9830

                                       17
<PAGE>
 
  You should rely only on the information provided in this prospectus or
incorporated by reference.  We have not authorized anyone to provide you with
different information.  You should not assume that the information in this
prospectus is accurate as of any date other than the date on the first page of
the prospectus.  Adelphia is not making this offer of securities in any state or
country in which the offer or sale is not permitted.

                                       18
<PAGE>
 
                                INDEMNIFICATION

  Adelphia's Bylaws provide that Adelphia shall, to the full extent permitted by
the Delaware General Corporation Law, indemnify certain persons whom it has the
power to indemnify pursuant thereto, including officers and directors of
Adelphia. The Bylaws also authorize Adelphia to maintain insurance to cover such
liabilities.

  Insofar as indemnification for liabilities arising under the Securities Act
may be permitted to directors, officers and persons controlling Adelphia
pursuant to the foregoing provisions, Adelphia has been informed that in the
opinion of the Commission, such indemnification is against public policy as
expressed in the Securities Act and is therefore unenforceable.

                                    EXPERTS

  The consolidated financial statements of Adelphia and its subsidiaries as of
March 31, 1997 and 1998, and for each of the three years in the period ended
March 31, 1998, and the consolidated financial statements of Olympus and its
subsidiaries as of December 31, 1996 and 1997, and for each of the three years
in the period ended December 31, 1997, all incorporated in this prospectus by
reference from Adelphia's Annual Report on Form 10-K for the year ended March
31, 1998, have been audited by Deloitte & Touche LLP, independent auditors, as
stated in their reports, which are incorporated herein by reference, and have
been so incorporated in reliance upon the reports of such firm given upon their
authority as experts in accounting and auditing.

                                       19
<PAGE>
 
                                    PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

  This Registration Statement relates to the Adelphia Communications Corporation
1998 Long-Term Incentive Compensation Plan. Adelphia Communications Corporation
("Adelphia") is incorporated in the State of Delaware.

Item 3.   Incorporation of Documents by Reference

  The following documents filed with the SEC by Adelphia are incorporated herein
by reference:

  (a) The latest annual report of Adelphia filed on Form 10-K for the fiscal
year ended March 31, 1998;

  (b) All other reports, if any, filed pursuant to Section 13(a) or 15(d) of the
Exchange Act since the end of the fiscal year covered by Adelphia's report
referred to in (a) above; and

  (c) The description of Adelphia's Class A Common Stock, par value $.01 per
share, as set forth in (i) Adelphia's registration statement filed with the SEC
under Section 12 of the Exchange Act and amendments and reports filed to update
such description and (ii) Adelphia's Registration Statement on Form S-3 and
accompanying prospectus filed pursuant to Rule 424(b)(5) filed with the SEC on
August 13, 1998 (File Number 333-58749).

  All documents subsequently filed by the Registrant with the SEC pursuant to
Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act, prior to the filing of
a post-effective amendment to this Registration Statement, which indicate that
all securities offered have been sold or which deregister all securities then
remaining unsold shall be deemed to be incorporated by reference in this
Registration Statement and to be a part hereof from the date of filing of such
documents.

Item 4.   Description of Securities

  Not applicable.

Item 5.  Interests of Named Experts and Counsel

  Not applicable.

Item 6.  Indemnification of Directors and Officers

  Section 145 of the Delaware General Corporation Law (the "DGCL") empowers a
Delaware corporation to indemnify any persons who are, or are threatened to be
made, parties to any threatened, pending or completed legal action, suit or
proceeding, whether civil, criminal, administrative or investigative (other than
an action by or in the right of such corporation), by reason of the fact that
such person was an officer or director of such corporation, or is or was serving
at the request of such corporation as a director, officer, employee or agent of
another corporation or enterprise.  The indemnity may include expenses
(including attorneys' fees), judgments, fines and amounts paid in settlement
actually and reasonably incurred by such person in connection with such action,
suit or proceeding, provided that such officer or director acted in good faith
in a manner he or she reasonably believed to be in or not opposed to the
corporation's best interests, and, for criminal proceedings, had no reasonable
cause to believe his or her conduct was illegal.  A Delaware corporation may
indemnify officers and directors in an action by or in the right of the
corporation under the same conditions, except that no indemnification is
permitted without judicial approval if the officer or director is adjudged to be
liable to the corporation in the performance of his or her duty.  Where an
officer or director is successful on the merits or otherwise in the defense of
any action referred to above, the corporation must indemnify him or her against
the expenses which such officer or director actually and reasonably incurred.
Adelphia's Bylaws provide for the indemnification of directors, officers and
employees of Adelphia within the limitations of Section 145.

  In accordance with Section 102(b)(7) of the DGCL, Adelphia's Restated
Certificate of Incorporation provides that directors shall not be personally
liable for monetary damages for breaches of their fiduciary duty as directors,

                                       20
<PAGE>
 
except for (i) breaches of their duty of loyalty to Adelphia or its
stockholders, (ii) acts or omissions not in good faith or which involve
intentional misconduct or knowing violations of law, (iii) certain transactions
under Section 174 of the DGCL (unlawful payment of dividends or unlawful stock
purchases or redemptions), or (iv) transactions from which a director derives an
improper personal benefit.  The effect of the provision is to eliminate the
personal liability of directors for monetary damages for actions involving a
breach of their fiduciary duty of care, including any actions involving gross
negligence.

Item 7.  Exemption From Registration Claimed

  Not applicable.

Item 8.  Exhibits

  The following is a list of exhibits filed as part of this Registration
Statement, which are incorporated herein:

<TABLE>
<CAPTION>
Exhibit No.    Reference
-------------  ---------
<C>            <S>                                                <C>
         4.01  Certificate of Incorporation of Adelphia           Incorporated herein by reference is Exhibit 3.01
               Communications Corporation                         to Registrant's Current Report on Form 8-K dated
                                                                  July 24, 1997.  (File No. 0-16014)

         4.02  Bylaws of Adelphia Communications Corporation      Incorporated herein by reference is Exhibit 3.02
                                                                  to Registrant's Annual Report on Form 10-K for the
                                                                  fiscal year ended March 31, 1994.  (File No. 0-16014)

         4.03  Adelphia Communications Corporation 1998           Incorporated herein by reference is Exhibit A to
               Long-Term Incentive Compensation Plan              Registrant's Proxy Statement for the Annual
                                                                  Meeting of Stockholders held on October 6, 1998.
                                                                  (File No. 0-16014)

         5.01  Opinion of Buchanan Ingersoll Professional         Filed herewith.
               Corporation

        23.01  Consent of Deloitte & Touche LLP                   Filed herewith.

        23.02  Consent of Buchanan Ingersoll Professional         Contained in opinion filed as Exhibit 5.01.
               Corporation

        24.01  Power of Attorney                                  Contained on signature page.
</TABLE>

Item 9.  Undertakings

  (a) The undersigned Registrant hereby undertakes:

  (1) To file, during any period in which offers or sales are being made, a
post-effective amendment to this Registration Statement:

     (i)   to include any prospectus required by Section 10(a)(3) of the
           Securities Act;

     (ii)  to reflect in the prospectus any facts or events, arising after the
           effective date of the Registration Statement (or the most recent
           post-effective amendment thereof) which, individually or in the
           aggregate, represent a fundamental change in the information set
           forth in the Registration Statement; and

                                       21
<PAGE>
 
     (iii) to include any material information with respect to the plan of
           distribution not previously disclosed in this Registration Statement
           or any material change to such information in this Registration
           Statement;

provided however, that subclauses (a)(1)(i) and (a)(1)(ii) do not apply if the
information required to be included in a post-effective amendment by the
foregoing clause is contained in periodic reports filed by Adelphia pursuant to
Section 13 or Section 15(d) of the Exchange Act that are incorporated by
reference in the Registration Statement;

  (2) That, for the purpose of determining any liability under the Securities
Act, each such post-effective amendment 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; and

  (3) To remove from registration by means of a post-effective amendment any of
the securities being registered which remain unsold at the termination of the
offering.

  (b)  Filings Incorporating Subsequent Exchange Act Documents by Reference.

  The undersigned Registrant hereby undertakes that, for purposes of determining
any liability under the Securities Act of 1933, each filing of the Registrant's
annual report pursuant to Section 13(a) or Section 15(d) of the Exchange Act
(and, where applicable, each filing of an employee benefit plan's annual report
pursuant to Section 15(d) of the Exchange Act) that is incorporated by reference
in this Registration Statement 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.

  (c) Request for Acceleration of Effective Date.

  Insofar as indemnification for liabilities arising under the Securities Act
may be permitted to directors, officers and controlling persons of Adelphia
pursuant to the provisions described in Item 6 of this Registration Statement,
or 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 of 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.

                                       22
<PAGE>
 
                                   SIGNATURES

  Pursuant to the requirements of the Securities Act, the Registrant certifies
that it has reasonable grounds to believe that it meets all of the requirements
for filing on Form S-8 and has duly caused this registration statement to be
signed on its behalf by the undersigned, thereunto duly authorized, in the City
of Coudersport, Commonwealth of Pennsylvania, on the 6th day of April, 1999.

                                 ADELPHIA COMMUNICATIONS CORPORATION

                                 By: /s/ Timothy J. Rigas
                                     --------------------
                                     Timothy J. Rigas
                                     Executive Vice President, Chief Accounting
                                     Officer, Chief Financial Officer and
                                     Treasurer

                               POWER OF ATTORNEY

  KNOW ALL MEN BY THE PRESENTS that each person whose signature appears below
constitutes and appoints John J. Rigas, Michael J. Rigas, Timothy Rigas, James
P. Rigas and Daniel R. Milliard, and each of them, such person's true and lawful
attorneys-in-fact and agents, with full power of substitution and revocation,
for such person and in such person's name, place and stead, in any and all
amendments (including post-effective amendments to this Registration Statement)
and to file the same with all exhibits thereto, and other documents in
connection therewith, with the Securities and Exchange Commission, granting unto
said attorneys-in-fact and agents, and each of them, full power and authority to
do and perform each and every act and thing requisite and necessary to be done,
as fully to all intents and purposes as such person might or could do in person,
hereby ratifying and confirming all that said attorneys-in-fact and agents or
any of them, or their or his substitute or substitutes, may lawfully do or cause
to be done by virtue hereof.

  Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed by the following persons in the capacities and on the
dates indicated.

<TABLE>
<CAPTION>
          SIGNATURE                                      TITLE                                DATE
<S>                             <C>                                                       <C>
/s/ John J. Rigas               Chairman, President and Chief Executive Officer           April 6, 1999
------------------------------ 
John J. Rigas

/s/ Michael J. Rigas            Executive Vice President and Director                     April 6, 1999
------------------------------ 
Michael J. Rigas

/s/ Timothy J. Rigas            Executive Vice President, Chief Accounting Officer,       April 6, 1999
------------------------------  Treasurer, Chief Financial Officer and Director
Timothy J. Rigas               

/s/ James P. Rigas              Executive Vice President and Director                     April 6, 1999
------------------------------ 
James P. Rigas

/s/ Daniel R. Milliard          Senior Vice President, Secretary and Director             April 6, 1999
------------------------------ 
Daniel R. Milliard

                                Director                                                  April __, 1999
------------------------------
Dennis P. Coyle

                                Director                                                  April __, 1999
------------------------------ 
Pete J. Metros

                                Director                                                  April __, 1999
------------------------------ 
Perry S. Patterson
</TABLE>

                                       23
<PAGE>
 
                                 EXHIBIT INDEX
                                 -------------

<TABLE>
<CAPTION>
Exhibit No.                                                Description
<C>            <S>                                                <C>
         4.01  Certificate of Incorporation of Adelphia           Incorporated herein by reference is Exhibit 3.01
               Communications Corporation                         to the Registrant's Current Report on Form 8-K
                                                                  dated July 24, 1997.  (File No. 0-16014)

         4.02  Bylaws of Adelphia Communications Corporation      Incorporated herein by reference is Exhibit 3.02
                                                                  to Registrant's Annual Report on Form 10-K for
                                                                  the fiscal year ended March 31, 1994.  (File No. 0-16014)

         4.03  Adelphia Communications Corporation 1998           Incorporated herein by reference is Exhibit A to
               Long-Term Incentive Compensation Plan              Registrant's Proxy Statement for the Annual
                                                                  Meeting of Stockholders held on October 6, 1998.
                                                                  (File No. 0-16014)

         5.01  Opinion of Buchanan Ingersoll Professional         Filed herewith.
               Corporation

        23.01  Consent of Deloitte & Touche LLP                   Filed herewith.

        23.02  Consent of Buchanan Ingersoll Professional         Contained in opinion filed as Exhibit 5.01.
               Corporation

        24.01  Power of Attorney                                  Contained on signature page.
</TABLE>

                                       24
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 79668}]
{"company-data": {"conformed-name": "ADELPHIA COMMUNICATIONS CORP", "cik": "0000796486", "assigned-sic": "4841", "irs-number": "232417713", "state-of-incorporation": "DE", "fiscal-year-end": "0331"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-75741", "film-number": "99588183"}, "business-address": {"street1": "MAIN AT WATER STREET", "city": "COUDERSPORT", "state": "PA", "zip": "16915", "phone": "8142749830"}, "mail-address": {"street1": "MAIN AT WATER STREET", "city": "COUDERSPORT", "state": "PA", "zip": "16915"}}
As filed with the Securities and Exchange Commission on April 6, 1999

                                                Registration No. 333-___________

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON D.C. 20549
                ________________________________________________
                                    FORM S-8
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                ________________________________________________
                      ADELPHIA COMMUNICATIONS CORPORATION

           Delaware                         4841                 23-2417713
  (State or jurisdiction of     (Primary Standard Industrial  (I.R.S. Employer
incorporation or organization)  Classification Code Number)  Identification No.)

                              Main at Water Street
                        Coudersport, Pennsylvania 16915
                    (Address of principal executive offices)
                  ___________________________________________
                      ADELPHIA COMMUNICATIONS CORPORATION
                   1998 LONG-TERM INCENTIVE COMPENSATION PLAN
                            (Full title of the plan)
                  ___________________________________________
Colin H. Higgin, Esquire                                  Copies of communications to:
        Deputy General Counsel                                Carl E. Rothenberger, Jr., Esquire
  Adelphia Communications Corporation                      Buchanan Ingersoll Professional Corporation
         Main at Water Street                                          One Oxford Centre
    Coudersport, Pennsylvania 16915                              301 Grant Street, 21st Floor
(Name and address of agent for service)                            Pittsburgh, PA 15219-1410
            (814) 274-9830                                              (412) 562-8826
(Telephone number of agent for service)
===================================================================================================================================
                                                       CALCULATION OF REGISTRATION FEE
===================================================================================================================================
                                                                Proposed Maximum         Proposed Maximum
                                         Amount to Be          Offering Price Per       Aggregate Offering           Amount of
Title of Securities to Be Registered     Registered(1)              Share(2)                  Price              Registration Fee(3)

------------------------------------------------------------------------------------------------------------------------------------
Class A Common Stock                        3,500,000                $61.50                $215,250,000              $59,839.50 
(par value $.01 per share)
------------------------------------------------------------------------------------------------------------------------------------

Total                                       3,500,000                $61.50                $215,250,000              $59,839.50
------------------------------------------------------------------------------------------------------------------------------------
(1) The provisions of Rule 416 of the Securities Act of 1933, as amended (the
    "Securities Act") shall apply to the number of shares registered on this
    Registration Statement and shall automatically increase or decrease as a
    result of stock splits, stock dividends or similar transactions.

(2) Estimated solely for purposes of calculating the registration fee pursuant
    to Rule 457(h) of the Securities Act. In accordance with Rule 457(h) of the
    Securities Act, such price is the average of the high and low sale prices
    for the Common Stock as quoted on the Nasdaq National Market on March 29,
    1999.

(3) Calculated pursuant to Section 6(B) of the Securities Act.
3,500,000 shares
ADELPHIA COMMUNICATIONS CORPORATION
Class A common stock
The stockholders of Adelphia            preferential rights with respect to
Communications Corporation as           cash dividends and distributions upon
described in the caption "Selling       the liquidation of Adelphia.  Holders
Stockholders" on page 15 of this        of Class B common stock are entitled
prospectus are offering and selling     to greater voting rights than the
up to 3,500,000 shares of Adelphia's    holders of Class A common stock;
Class A common stock under this         however, the holders of Class A
prospectus.                             common stock, voting as a separate
                                        class, are entitled to elect one of
The Class A common stock is listed on   Adelphia's directors.
the Nasdaq National Market.  The      
Class A common stock's ticker symbol    You should carefully review "Risk
is "ADLAC."  On April 1, 1999, the      Factors" beginning on page 6 for a
closing sale price on the Nasdaq        discussion of things you should
National Market of a single share of    consider when investing in Class A
the Class A common stock was $63.25.    common stock.
 
Our common stock also includes Class    Neither the SEC nor any state
B common stock.  The rights of          securities commission has approved or
holders of the Class A common stock     disapproved of these securities or
and Class B common stock differ with    passed upon the adequacy or accuracy
respect to certain aspects of           of this prospectus.  Any
dividends, liquidations and voting.     representation to the contrary is a
The Class A common stock has            criminal offense.
The date of this prospectus is April 6, 1999.

                                       2
TABLE OF CONTENTS

                                                                            Page
                                                                            ----
Adelphia...................................................................   4
Risk Factors...............................................................   6
Dilution...................................................................  15
Selling Stockholders.......................................................  15
Use of Proceeds............................................................  15
Plan of Distribution.......................................................  15
Where You Can Find More Information........................................  16
Indemnification............................................................  19
Experts....................................................................  19

                                       3
ADELPHIA

  Adelphia is a leader in the telecommunications industry with cable television
and local telephone operations.  Our operations consist of providing
telecommunications services primarily over our networks, which are commonly
referred to as broadband networks because they transmit large quantities of
voice, video and data by way of digital or analog signals.  As of December 31,
1998, we owned or managed cable television systems with broadband networks that
passed in front of 3,252,830 homes and served 2,304,325 basic subscribers.  John
J. Rigas, the Chairman, President, Chief Executive Officer and founder of
Adelphia, has owned and operated cable television systems since 1952.

  We own cable systems in twelve states which are organized into seven regional
clusters: Western New York, Virginia, Western Pennsylvania, New England, Eastern
Pennsylvania, Ohio and New Jersey. These systems are located primarily in
suburban areas of large and medium-sized cities within the 50 largest television
markets. As of December 31, 1998, the broadband networks for these systems
passed in front of 2,131,978 homes and served 1,528,307 basic subscribers.

  We also provide management and consulting services to other partnerships and
corporations engaged in the ownership and operation of cable television systems.
John J. Rigas and members of his immediate family, including entities they own
or control, have substantial ownership interests in these partnerships and
corporations. As of December 31, 1998, the broadband networks for cable systems
owned by these Rigas family partnerships and corporations passed in front of
177,250 homes and served 134,443 basic subscribers.

  We also own a 50% voting interest and nonvoting preferred limited partnership
interests in Olympus Communications, L.P.  Olympus is a joint venture limited
partnership that operates a large cable system in Florida.  As of December
31, 1998, the broadband networks for this system passed in front of 943,602
homes and served 641,575 basic subscribers.

  Through our subsidiary, Hyperion Telecommunications, Inc., we own and operate
a large competitive local exchange carrier in the eastern United States.  This
means that Hyperion provides its customers with alternatives to the incumbent
local telephone company for local telephone and telecommunications services.
Hyperion's telephone operations are referred to as being facilities based, which
means it generally owns the local telecommunications networks and facilities it
uses to deliver these services, rather than leasing or renting the use of
another party's networks to do so.  As of December 31, 1998, Hyperion managed
and operated 22 telecommunications networks, including two under construction,
serving 46 markets.  Hyperion's Class A common stock is listed on the Nasdaq
National Market under the symbol "HYPT."

  Our executive offices are located at Main at Water Street, Coudersport,
Pennsylvania 16915, and our telephone number is (814) 274-9830.

Recent Developments

  On March 5, 1999, Adelphia announced that it had entered into a definitive
agreement to acquire Century Communications Corporation by merger.  Under the
agreement, Adelphia would acquire 100% of the outstanding common stock of
Century for an aggregate of approximately $826,000,000 in cash, 48,700,000
shares of Class A common stock and the assumption of approximately
$1,600,000,000 of debt.  This transaction is subject to shareholder approval by
Century and Adelphia and other customary closing conditions.  As of March 5,
1999, Century had approximately 1,600,000 basic subscribers after giving effect
to Century's pending joint venture with Tele-Communications, Inc.

  On March 2, 1999, Hyperion issued $300,000,000 of 12% Senior Subordinated
Notes due 2007.  An entity controlled by members of the Rigas family purchased
$100,000,000 of the $300,000,000 of Senior Subordinated Notes directly from
Hyperion at a price equal to the aggregate principal amount less the discount to
the initial purchasers.  The net proceeds of approximately $292,000,000 will be
used to fund Hyperion's acquisition of interests held by local partners in
certain of its networks, for capital expenditures and investments in its
networks, for working capital purposes and for general corporate purposes.

                                       4
On February 23, 1999, Adelphia announced that it had entered into a definitive
agreement to acquire FrontierVision Partners, L.P. for approximately
$2,100,000,000.  Under that agreement Adelphia would acquire 100% of
FrontierVision in exchange for approximately $550,000,000 in cash, 7,000,000
shares of Adelphia Class A common stock and the assumption of approximately
$1,110,000,000 of debt.  The transaction is subject to customary closing
conditions.  As of February 23, 1999, FrontierVision had approximately 702,000
basic subscribers.

  On January 29, 1999, Adelphia purchased from Telesat Cablevision, Inc., a
subsidiary of FPL Group, Inc., shares of Adelphia's stock owned by Telesat.
Adelphia purchased 1,091,524 shares of Class A common stock and the 20,000
shares of Series C Cumulative Convertible preferred stock which are convertible
into an additional 2,358,490 shares of Class A common stock.  These shares
represent 3,450,014 shares of common stock on a fully converted basis.  Adelphia
and Telesat also agreed to a redemption of Telesat's interests in Olympus by
July 11, 1999.  The redemption transaction is subject to applicable approvals of
third parties or governmental authorities.  The aggregate purchase price for
these transactions will be approximately $257,200,000.

  On January 21, 1999, Adelphia acquired Verto Communications, Inc.  Verto
provided cable television services to approximately 56,000 subscribers in the
greater Scranton, Pennsylvania area at the date of acquisition.  In connection
with the Verto acquisition, Adelphia issued 2,561,024 shares of its Class A
common stock to the former owners of Verto.

  On January 14, 1999, Adelphia completed offerings totaling 8,600,000 shares of
its Class A common stock.  In those offerings, Adelphia sold 4,600,000 newly
issued shares of Class A common stock to Goldman, Sachs & Co. at $43.25 per
share and it also sold 4,000,000 shares of its Class A common stock at $43.25
per share to a Rigas family partnership.  Adelphia used the proceeds of about
$372,000,000 from these offerings to repay subsidiary bank debt, which may be
reborrowed and used for general corporate purposes.

  On January 13, 1999, Adelphia completed offerings of $100,000,000 of 7 1/2%
Senior Notes due 2004 and $300,000,000 of 7 3/4% Senior Notes due 2009.  Net
proceeds from these offerings, after deducting offering expenses, were
approximately $393,700,000.  Of this amount, Adelphia used approximately
$160,000,000 to redeem a portion of its 9 1/2% Senior Pay-In-Kind Notes due
2004.  Adelphia used the remainder to repay borrowings under revolving credit
facilities of its subsidiaries which may be reborrowed and used for general
corporate purposes.  The terms of these notes are similar to those of Adelphia's
existing publicly held senior debt.

  On December 30, 1998, Adelphia's 66.7% owned joint venture limited partnership
with Tele-Communications, Inc., which has operations in the Western New York
region, completed a $700,000,000, eight and one-half year credit facility.  The
credit facility consists of a $350,000,000 reducing revolving credit portion and
a $350,000,000 term loan portion.  The partnership used proceeds from initial
borrowings to repay indebtedness owed to Adelphia.

                                       5
RISK FACTORS

   Before you invest in Adelphia's Class A common stock, you should be aware
that there are various risks, including those described below. You should
consider carefully these risk factors together with all of the other information
included in this prospectus before you decide to purchase any shares of
Adelphia's Class A common stock.
High Level Of                Adelphia has a substantial amount of debt.  We borrowed this money to
Indebtedness              purchase and to expand our cable systems and other operations and, to a
-------------             lesser extent, for investments and loans to our affiliates.  At December
As of December 31,        31, 1998, our indebtedness totaled approximately $3,527,452,000.  This
1998, we owe              included approximately:
approximately $3.5        .  $1,810,212,000 of Adelphia Parent Company public debt.  When we use
billion.  Our high           the term "Adelphia Parent Company" in this prospectus, we are referring
level of                     only to Adelphia Communications Corporation as a parent holding company
indebtedness can             entity, and not to its subsidiaries;
have important            .  $1,246,456,000 of debt owed by our subsidiaries to banks, other
adverse consequences         financial institutions and other persons; and
to us and to you.         .  $470,784,000 of public debt owed by Hyperion.
 
 
Debt service consumes a      Our high level of indebtedness can have important adverse consequences to
substantial portion of    us and to you.  It requires that we spend a substantial portion of the
the cash we generate.     cash we get from our business to repay the principal and interest on
This could affect our     these debts.  Otherwise, we could use these funds for general corporate
ability to invest in      purposes or for capital improvements.  Our ability to obtain new loans
our business in the       for working capital, capital expenditures, acquisitions or capital
future as well as to      improvements may be limited by our current level of debt.  In addition,
react to changes in       having such a high level of debt could limit our ability to react to
our industry or           changes in our industry and to economic conditions generally.  In
economic downturns.       addition to our debt, at December 31, 1998, the Adelphia Parent Company
                          also had approximately $148,191,000 and Hyperion had approximately
                          $228,674,000 of redeemable exchangeable preferred stock which contain
                          payment obligations that are similar to our debt obligations in these
                          respects.  Olympus also has a substantial amount of debt.

Approximately 32% of         Our debt comes due at various times up to the year 2009, including an
this debt must be paid    aggregate of approximately $1,126,169,000 which, as of December 31, 1998,
by April 1, 2003 and      we must pay by April 1, 2003.
all of it must be paid    
by 2009.                  

Our Business Requires        Our business requires substantial additional financing on a continuing
Substantial Additional    basis for capital expenditures and other purposes including:
Financing And If We Do    .  constructing and upgrading our plant and networks--some of these
Not Obtain That              upgrades we must make to comply with the requirements of local cable
Financing We May Not         franchise authorities,
Be Able To Upgrade Our    .  offering new services,
Plant, Offer Services,    .  scheduled principal and interest payments,
Make Payments When Due    .  refinancing existing debt, and
Or Refinance Existing     .  acquisitions and investments.
Debt                      
----------------------
6
There can be no guarantee that we will be able to issue additional debt
                          or sell stock or other additional equity on satisfactory terms, or at
                          all, to meet our future financing needs.

We Have Had Large            The Total Convertible Preferred Stock, Common Stock and Other
Losses And Negative       Stockholders' Equity (Deficiency) at December 31, 1998 was a deficit of
Stockholders' Equity      approximately $1,021,746,000.  Our continuing net losses, which are
And We Expect This To     mainly due to our high levels of depreciation and amortization and
Continue                  interest expense, have created this deficiency.  Our recent net losses
---------------------     applicable to our common stockholders were approximately as follows for
                          the periods specified:
                          .  fiscal year ended March 31, 1996 - $119,894,000;
                          .  fiscal year ended March 31, 1997 - $130,642,000;
                          .  fiscal year ended March 31, 1998 - $192,729,000; and
                          .  nine months ended December 31, 1998 - $135,848,000.

                             We expect to continue to incur large net losses for the next several
                          years.

Our earnings have been       Our earnings could not pay for our combined fixed charges and preferred
insufficient to pay       stock dividends during these periods by the amounts set forth in the
for our fixed charges     table below, although combined fixed charges and preferred stock
and preferred stock       dividends included substantial non-cash charges for depreciation,
dividends.                amortization and non-cash interest expense on some of our debts and the
                          non-cash expense of Hyperion's preferred stock dividends:

                                                                     Earnings          Non-Cash
                                                                    Deficiency          Charges
                                                                  ---------------  -----------------
                          .  fiscal year ended March 31, 1996        $ 78,189,000       $127,319,000
                          .  fiscal year ended March 31, 1997        $ 61,848,000       $165,426,000
                          .  fiscal year ended March 31, 1998        $113,941,000       $195,153,000
                          .  nine months ended December 31, 1998     $116,899,000       $186,022,000
7
If we could not              Historically, the cash we generate from our operating activities and
refinance our debt or     borrowings has been sufficient to meet our requirements for debt service,
obtain new loans, we      working capital, capital expenditures, and investments in and advances to
would likely have to      our affiliates, and we have depended on getting additional borrowings to
consider various          meet our liquidity requirements.  Although in the past we have been able
options such as the       both to refinance our debt and to obtain new debt, there can be no
sale of additional        guarantee that we will be able to continue to do so in the future or that
equity or some of our     the cost to us or the other terms which would affect us would be as
assets to meet the        favorable to us as our current loans and credit agreements.  We believe
principal and interest    that our business will continue to generate cash and that we will be able
payments we owe,          to obtain new loans to meet our cash needs.  However, the covenants in
negotiate with our        the indentures and credit agreements for our current debt limit our
lenders to restructure    ability to borrow more money.
existing loans or         
explore other options     
available under           
applicable laws           
including those under     
reorganization or         
bankruptcy laws. We       
can not guarantee that    
any options available     
to us would enable us     
to repay our debt in      
full.

Competition                  The telecommunications services provided by Adelphia are subject to
-----------               strong competition and potential competition from various sources.  Our
                          cable television systems compete with other means of distributing video
Our cable television      to home televisions such as Direct Broadcast Satellite systems, commonly
business is subject to    known as DBS systems, and Multichannel Multipoint Distribution systems.
strong competition        Some of the regional Bell telephone operating companies and other local
from several sources      telephone companies are in the process of entering the video-to-home
which could adversely     business and several have expressed their intention to enter the
affect revenue or         video-to-home business.  In addition, some regional Bell operating
revenue growth.           companies and local telephone companies have facilities which are capable
                          of delivering cable television service.  The equipment which telephone
                          companies use in providing local exchange service may give them
                          competitive advantages over us in distributing video to home televisions.
                          The regional Bell operating companies and other potential competitors
                          have much greater resources than Adelphia and would constitute formidable
                          competition for our cable television business.  We cannot predict either
                          the extent to which competition will continue to materialize or, if such
                          competition materializes, the extent of its effect on our cable
                          television business.
 
                             We also face competition from other communications and entertainment
                          media, including conventional off-air television broadcasting services,
                          newspapers, movie theaters, live sporting events and home video products.
                          We cannot predict the extent to which competition may affect us.

Hyperion's operations        In each of the markets served by Hyperion's networks, the competitive
are also subject to       local exchange carrier services offered by Hyperion compete principally
risk because Hyperion     with the services offered by the incumbent local telephone exchange
competes principally      carrier company serving that area.  Local telephone companies have
with established local    long-standing relationships with their customers, have the potential to
telephone carriers        subsidize competitive services from monopoly service revenues, and
that have                 benefit from favorable state and federal regulations.  The merger of Bell Atlantic 
long-standing
8
utility                   and NYNEX created a very large company whose combined territory
relationships with        covers a substantial portion of Hyperion's markets.  Other combinations
their customers and       are occurring in the industry, which may have a material adverse effect
pricing flexibility       on Hyperion and us.
for local telephone       
services.                 
                             We think that local telephone companies will gain increased pricing
                          flexibility from regulators as competition increases.  Hyperion's
                          operating results and cash flow could be materially and adversely
                          affected by actions by regulators, including permitting the incumbent
                          local telephone companies in Hyperion's markets to do the following:
                          .  lower their rates substantially;
                          .  engage in aggressive volume and term discount pricing practices for
                             their customers; or
                          .  charge excessive fees to Hyperion for interconnection to the incumbent
                             local telephone company's networks.

If the regional Bell         The regional Bell operating companies can now obtain regulatory approval
telephone companies       to offer long distance services if they comply with the interconnection
could get regulatory      requirements of the federal Telecommunications Act of 1996.  To date, the
approval to offer long    FCC has denied the requests for approval filed by regional Bell operating
distance service in       companies in Hyperion's operating areas.  However, an approval of such a
competition with          request could result in decreased market share for the major long
Hyperion's significant    distance carriers which are among Hyperion's significant customers.  This
customers, some of        could have a material adverse effect on Hyperion.
Hyperion's major          
customers could lose      
market share.             

The regional Bell            Regional Bell operating companies have also recently filed petitions with
telephone companies       the FCC requesting waivers of other obligations under the
continue to seek other    Telecommunications Act of 1996.  These involve services the Company also
regulatory approvals      provides such as high speed data, long distance, and services to Internet
that could                Service Providers.  If the FCC grants the regional Bell operating
significantly enhance     companies' petitions, this could have a material adverse effect on
their competitive         Hyperion.
position against          
Hyperion.                 

Potential competitors        Potential competitors for Hyperion include other competitive local
to Hyperion's             exchange carriers, incumbent local telephone companies which are not
telecommunications        subject to regional Bell operating companies' restrictions on offering
services include the      long distance service, AT&T, MCIWorldCom, Sprint and other long distance
regional Bell             carriers, cable television companies, electric utilities, microwave
telephone companies,      carriers, wireless telecommunications providers and private networks
AT&T, MCIWorldCom and     built by large end users.  Both AT&T and MCIWorldCom have announced that
Sprint, electric          they have begun to offer local telephone services in some areas of the
utilities and other       country, and AT&T recently announced a new wireless technology for
companies that have       providing local telephone service.  AT&T and Tele-Communications, Inc.
advantages over           have merged.  Although Hyperion has good relationships with the long
Hyperion.                 distance carriers, they could build their own facilities, purchase other
                          carriers or their facilities, or resell the services of other carriers
                          rather than use Hyperion's services when entering the market for local
                          exchange services.
9
Many of Hyperion's current and potential competitors, particularly
                          incumbent local telephone companies, have financial, personnel and other
                          resources substantially greater than those of Hyperion, as well as other
                          competitive advantages over Hyperion.

We Are Subject To            The cable television industry and the provision of local telephone
Extensive Regulation      exchange services are subject to extensive regulation at the federal,
--------------------      state and local levels, and many aspects of such regulation are currently
                          the subject of judicial proceedings and administrative or legislative
Our cable television      proposals.  In particular, the FCC adopted regulations that limit our
and telecommunications    ability to set and increase rates for our basic and cable programming
businesses are heavily    service packages and for the provision of cable television-related
regulated as to rates     equipment.  The law permits certified local franchising authorities to
we can charge and         order refunds of rates paid in the previous twelve-month period
other matters.  This      determined to be in excess of the permitted reasonable rates.  It is
regulation could limit    possible that rate reductions or refunds of previously collected fees may
our ability to            be required in the future.
increase rates, cause                                                                               
us to decrease then          The cable television industry is subject to state and local regulations
current rates or          and we must comply with rules of the local franchising authorities to     
require us to refund      retain and renew our cable franchises, among other matters.  There can be 
previously collected      no assurances that the franchising authorities will not impose new and    
fees.                     more restrictive requirements as a condition to franchise renewal.        

The federal                  The federal Telecommunications Act of 1996 substantially changed federal,
Telecom-munications       state and local laws and regulations governing our cable television and
Act of 1996 may have a    telecommunications businesses.  This law could materially affect the
significant impact on     growth and operation of the cable television industry and the cable
our cable television      services we provide.  Although this legislation may lessen regulatory
and telephone             burdens, the cable television industry may be subject to new competition
businesses.               as a result.  There are numerous rulemakings that have been and continue
                          to be undertaken by the FCC which will interpret and implement the
                          provisions of this law.  Furthermore, portions of this law have been, and
                          likely other portions will be, challenged in the courts.  We cannot
                          predict the outcome of such rulemakings or lawsuits or the short- and
                          long-term effect, financial or otherwise, of this law and FCC rulemakings
                          on us.

                             Similarly, the Telecommunications Act of 1996 removes entry barriers for
                          all companies and could increase substantially the number of competitors
                          offering comparable services in Hyperion's markets or potential markets.
                          Furthermore, we cannot guarantee that rules adopted by the FCC or state
                          regulators or other legislative or judicial initiatives relating to the
                          telecommunications industry will not have a material adverse effect on
                          Hyperion.

Unequal Voting Rights        Adelphia has two classes of common stock -- Class A which carries one
Of Stockholders           vote per share and Class B which carries ten votes per share.  The shares
---------------------     being offered to you by this prospectus are Class A shares.  Under our
                          Certificate of Incorporation, the Class A shares elect only one of our
                          eight directors.
10
Control Of Voting Power      As of March 1, 1999, the Rigas family beneficially owned shares
By The Rigas Family       representing about 48% of the total number of outstanding shares of both
-----------------------   classes of Adelphia's common stock and about 81% of the total voting
                          power of Adelphia's shares.  The public holds a majority of the
The Rigas family can      outstanding Class A shares, although the Rigas family also owns about 36%
control stockholder       of those shares as of March 1, 1999.  The Rigas family owns about 99% of
decisions on very         Adelphia's Class B shares.  The Rigas family also owns shares of
important matters.        Adelphia's 8% Series C Cumulative Convertible preferred stock which, if
                          converted, would increase its voting power and beneficial ownership.  As
                          a result of the Rigas family's stock ownership and an agreement among the
                          Class B stockholders, members of the Rigas family have the power to elect
                          seven of eight Adelphia directors, and if they converted their
                          Convertible preferred stock might be able to elect all eight directors.
                          In addition, the Rigas family could control stockholder decisions on
                          other matters such as amendments to our Certificate of Incorporation and
                          Bylaws, and mergers or other fundamental corporate transactions.
 
There Are Potential          John J. Rigas and the other executive officers of Adelphia, including
Conflicts Of Interest     other members of the Rigas family, own other corporations and
Between Adelphia And      partnerships, which are managed by us for a fee.  Subject to the
The Rigas Family          restrictions contained in a business opportunity agreement regarding
---------------------     future acquisitions, Rigas family members and the executive officers are
                          free to continue to own these interests and acquire additional interests
                          in cable television systems.  These activities could present a conflict
                          of interest with us, such as how much time our executive officers devote
                          to our business.  In addition, there have been and will continue to be
                          transactions between us and the executive officers or the other entities
                          they own or have affiliations with.  Our public debt indentures contain
                          covenants that place some restrictions on transactions between us and our
                          affiliates.

Holding Company              The Adelphia Parent Company directly owns no significant assets other
Structure And             than stock, partnership interests, equity and other interests in our
Potential Impact Of       subsidiaries and in other companies.  This creates risks regarding our
Restrictive Covenants     ability to provide cash to the Adelphia Parent Company to repay the
In Subsidiary Debt        interest and principal which it owes, our ability to pay cash dividends
Agreements                to our common stockholders in the future, and the ability of our
---------------------     subsidiaries and other companies to respond to changing business and
                          economic conditions and to get new loans.

The Adelphia Parent          The public indentures, and the credit agreements for bank and other
Company depends on its    financial institution loans, of our subsidiaries and other companies
subsidiaries and other    restrict their ability and the ability of the companies they own to make
companies in which it     payments to the Adelphia Parent Company.  These agreements also place
has investments, to       other restrictions on the borrower's ability to borrow new funds and
fund its cash needs.      include requirements for the borrowers to remain in compliance with the
                          loans.  The ability of a subsidiary or a company in which we have
                          invested to comply with debt restrictions may be affected by events that
                          are beyond our control.  The breach of any of these covenants could
                          result in a default which could result in all loans and other amounts
                          owed to its lenders, to be due and payable.  Our subsidiaries and
                          companies in which we have invested might not be able to repay in full
                          the accelerated loans.
11
It Is Unlikely You Will      Adelphia has never declared or paid cash dividends on any of its common
Receive A Return On       stock and has no intention of doing so in the foreseeable future.  As a
Your Shares Through       result, it is unlikely that you will receive a return on your shares
The Payment Of Cash       through the payment of cash dividends.
Dividends                 
-----------------------

Future Sales Of              Sales of a substantial number of shares of Class A common stock or Class
Outstanding Common        B common stock, including sales by any pledgees of such shares, could
Stock Could Adversely     adversely affect the market price of our Class A common stock and could
Affect The Market         impair our ability in the future to raise capital through stock offerings.
Price Of Our Common                                                                                     
Stock                        Under various registration rights agreements or arrangements, as of           
---------------------     January 26, 1999, the Rigas family has the right, subject to some             
                          limitations, to require Adelphia to register substantially all of the         
                          shares which it owns of the Class A common stock--15,029,119 shares,          
                          Class B common stock--10,736,544 shares and the equivalent number of          
                          shares of Class A common stock into which they may be converted, and          
                          Convertible preferred stock--80,000 shares and the 9,433,962 shares of        
                          Class A common stock into which they may be converted.  Among others,         
                          Adelphia has registered or agreed to register for public sale the             
                          following shares:                                                             
                          .  for the Rigas family -- up to 11,000,000 shares of Class A common
                             stock, 80,000 shares of Convertible preferred stock and the Class A
                             common stock issuable upon conversion of the Convertible preferred stock;
                          .  for Booth American Company -- 3,571,428 shares of Class A common stock
                             owned as of March 24, 1998;
                          .  for the selling stockholders receiving shares in the Verto acquisition
                             -- 2,561,024 shares of Class A common stock;
                          .  in connection with the January 14, 1999 equity offerings 4,000,000
                             shares of Class A common stock purchased by a Rigas family partnership;
                          .  in connection with the pending FrontierVision acquisition described in
                             Recent Developments, Adelphia has agreed to register 7,000,000 shares of
                             Class A common stock which Adelphia will issue at closing.  Adelphia will
                             also register 1,000,000 shares issued in connection with the
                             FrontierVision purchase agreement and the escrow arrangement under that
                             agreement for the benefit of the owners of  FrontierVision in the event
                             that transaction does not close; and
                          .  in connection with the pending Century acquisition described in Recent
                             Developments, Adelphia expects to register approximately 48,700,000 shares
                             of Class A common stock.

                             Approximately 14,904,000 shares of Class A common stock and up to 80,000
                          shares of Convertible preferred stock, including the underlying Class A
                          common stock, have been pledged in connection with margin loans made to
                          members of the Rigas family.  These pledgees could freely sell any shares
                          acquired upon a foreclosure.

Purchasers Of Our            Persons purchasing Class A common stock will incur immediate and
Common Stock Will         substantial net tangible book value dilution.
Incur Immediate           
Dilution                  
-----------------
12
Adelphia's Acquisitions      Because Adelphia is experiencing a period of rapid expansion through
And Expansion Could       acquisition, the operating complexity of Adelphia, as well as the
Involve Operational       responsibilities of management personnel, have increased.  Adelphia's
Risks                     ability to manage such expansion effectively will require it to continue
-----------------------   to expand and improve its operational and financial systems and to
                          expand, train and manage its employee base.

                             Both the Century and FrontierVision transactions involve the acquisition
                          of companies that have previously operated independently.  Adelphia may
                          not be able to integrate the operations of these companies without some
                          level of difficulty, such as the loss of key personnel.  There is no
                          guarantee that Adelphia will be able to realize the benefits expected
                          from the integration of operations from these transactions.

The Century Acquisition      The Century merger requires approvals from Century's shareholders and
May Not Be Completed      Adelphia's stockholders. Although under the merger and related agreements
If The Required           the Class B shareholders of Century and the controlling stockholders of
Approval of Century's     Adelphia have agreed to vote in favor of the merger, the companies cannot
Class A Shareholders      predict the ultimate outcome of the required vote of the Class A
Is Not Obtained           shareholders of Century.  If that vote is not obtained, the companies
-----------------------   might not be able to complete the proposed transaction as currently
                          structured or in a timely manner, if at all.

Year 2000 Issues             The year 2000 issue refers to the inability of computerized systems and
Present Risks To Our      technologies to recognize and process dates beyond December 31, 1999.
Business Operations In    This could present risks to the operation of our business in several
Several Ways              ways.  Our computerized business applications that could be adversely
----------------------    affected by the year 2000 issue include:
                          .  information processing and financial reporting systems,
                          .  customer billing systems,
                          .  customer service systems,
                          .  telecommunication transmission and reception systems, and
                          .  facility systems.

                             System failure or miscalculation could result in an inability to process
                          transactions, send invoices, accept customer orders or provide customers
                          with products and services.  Although we are evaluating the impact of the
                          year 2000 issue on our business and are seeking to implement necessary
                          solutions, this process has not been completed.

                             There can be no assurance that the systems of other companies on which
                          our systems rely will be year 2000 ready or timely converted into systems
                          compatible with our systems.  Our failure or a third-party's failure to
                          become year 2000 ready, or our inability to become compatible with third
                          parties with which we have a material relationship, may have a material
                          adverse effect on us, including significant service interruption or
                          outages; however, we cannot currently estimate the extent of any such
                          adverse effects.

Forward-Looking              The statements contained or incorporated by reference in this prospectus
Statements In This        that are not historical facts are "forward-looking statements" and can be
Prospectus Are Subject    identified by the use of forward-looking terminology such as "believes,"
To Risks And              "expects," "may," "will," "should," "intends" or "anticipates" or the
Uncertainties             negative thereof or other variations thereon or comparable terminology,
----------------------    or by discussions of strategy that involve risks and uncertainties.
13
Certain information set forth or incorporated by reference in this
                          prospectus, including "Management's Discussion and Analysis of Financial
                          Condition and Results of Operations" in Adelphia's 1998 Annual Report on
                          Form 10-K and in Adelphia's Form 10-Qs, is forward-looking, such as
                          information relating to the effects of future regulation, future capital
                          commitments and the effects of competition.  Such forward-looking
                          information involves important risks and uncertainties that could
                          significantly affect expected results in the future from those expressed
                          in any forward-looking statements made by, or on behalf of, us.  These
                          risks and uncertainties include, but are not limited to, uncertainties
                          relating to economic conditions, acquisitions and divestitures,
                          government and regulatory policies, the pricing and availability of
                          equipment, materials, inventories and programming, technological
                          developments, year 2000 issues and changes in the competitive environment
                          in which we operate.  Persons reading this prospectus are cautioned that
                          such statements are only predictions and that actual events or results
                          may differ materially.  In evaluating such statements, readers should
                          specifically consider the various factors which could cause actual events
                          or results to differ materially from those indicated by such
                          forward-looking statements.
14
DILUTION

  The net tangible book value of Adelphia's common stock as of December 31, 1998
was a deficit of approximately $2,050,905,000 or negative $48.72 a share.  Net
tangible book value per share represents the amount of Adelphia's convertible
preferred stock, common stock and other stockholders' equity (deficiency), less
intangible assets, divided by shares of Adelphia's common stock outstanding.
Purchasers of Class A common stock will have an immediate dilution of net
tangible book value which, due to our having a net tangible book value deficit,
will exceed the purchase price per share.  For example, in the January 14, 1999
equity offerings, the purchase price of a single share initially sold to the
public was $45.00 and the net tangible book value dilution per share was $78.53,
based on net tangible book value as of December 31, 1998. Net tangible book
value dilution per share represents the difference between the amount per share
paid by purchasers of shares of Class A common stock in an offering by Adelphia
and the pro forma net tangible book value per share of the common stock
immediately after completion of such offering.

                               SELLING STOCKHOLDERS

  As the names and amounts of securities to be sold by selling stockholders
become known, the following information about each selling stockholder will be
included in a prospectus supplement:  the name and position(s) over the last
three years with Adelphia of each selling stockholder; the number of shares of
Class A common stock owned by each selling stockholder; the number of shares of
Class A common stock available to be acquired by each selling stockholder
pursuant to the Plan and being registered for resale by the selling
stockholders; and the number of shares of Class A common stock and the
percentage, if 1% or more, of the total class of Class A common stock
outstanding to be beneficially owned by each selling stockholder following this
offering.

                                USE OF PROCEEDS

  All net proceeds from the sale of the shares will go to the stockholders who
offer and sell them.  We will not receive any proceeds from the sale of shares
by the selling stockholders.

                              PLAN OF DISTRIBUTION

  Adelphia is registering the shares on behalf of the selling stockholders.
References in this section to selling stockholders also includes any pledgees,
donees or transferees identified in a supplement to this prospectus as described
above.  The selling stockholders may offer their shares at various times in one
or more of the following transactions:

 .  in transactions, which may involve crosses or block transactions, on any
   national securities exchange or quotation service on which the shares may be
   listed or quoted at the time of sale;

 .  in the over-the-counter market;

 .  in private transactions other than in the over-the-counter market or on an
   exchange;

 .  in connection with short sales of shares;

 .  by pledge to secure debts and other obligations;

 .  in connection with the writing of non-traded and exchange-traded call
   options, in hedge transactions and in settlement of other transactions in
   standardized or over-the-counter options; or

 .  in a combination of any of the above transactions.

                                       15
The selling stockholders may sell their shares at market prices at the time of
sale, at prices related to market prices, at negotiated prices or at fixed
prices.

  The selling stockholders may use broker-dealers to sell their shares.  If this
happens, broker-dealers will either receive discounts or commissions from the
selling stockholders, or they will receive commissions from purchasers of shares
for whom they acted as agents.  The selling stockholders, any brokers, dealers
and any other participating brokers or dealers may be deemed to be
"underwriters" within the meaning of the Securities Act in connection
with these sales, and any profits realized or commissions received may be deemed
underwriting compensation.

  The selling stockholders may also enter into hedging transactions with broker-
dealers or other financial institutions.  In connection with these transactions,
broker-dealers or other financial institutions may engage in short sales of
Adelphia's Class A common stock in the course of hedging the positions they
assume with selling stockholders.  The selling stockholders may also enter into
options or other transactions with broker-dealers or other financial
institutions which require the delivery, to that broker-dealer or other
financial institution, the shares offered under this prospectus.  The shares
that broker-dealer or other financial institution receives in those types of
transactions may be resold under this prospectus.

  Selling stockholders also may resell all or a portion of the shares in open
market transactions in reliance upon Rule 144 under the Securities Act of 1933,
provided they meet the criteria and conform to the requirements of that Rule.

  When a particular offering of shares is made, if required, we will distribute
to you a prospectus supplement.  This supplement will set forth the names of the
selling stockholders, the aggregate amount of shares being offered, the number
of such securities owned prior to and after the completion of any such offering,
and, to the extent required, the terms of the offering, including the name or
names of any underwriters, broker-dealers or agents, any discounts, commissions
and other terms constituting compensation from the selling stockholders and any
discounts, commissions or concessions allowed or reallowed or paid to broker-
dealers.

  To comply with the securities law in some jurisdictions, the shares will be
offered or sold in particular jurisdictions only through registered or licensed
brokers or dealers.  In addition, in some jurisdictions the shares may not be
offered or sold unless they have been registered or qualified for sale in that
jurisdictions or an exemption from registration or qualification is available
and is complied with.

  To comply with rules and regulations under the  Exchange Act, persons engaged
in a distribution of the shares may be limited in their ability to engage in
market activities with respect to such shares.  In addition and without limiting
the foregoing, each selling stockholder will be subject to applicable provisions
of the Exchange Act and the rules and regulations thereunder, which provisions
may limit the timing of purchases and sales of any of the shares by the selling
stockholders.  All of these things may affect the marketability of the shares.

  All expenses of the registration of the shares will be paid by Adelphia,
including, without limitation, Commission filing fees and expenses of compliance
with state securities or "blue sky" laws; provided, however, that the selling
stockholders will pay all underwriting discounts and selling commissions, if
any.  The selling stockholders and Adelphia may enter into agreements in the
future regarding contribution and indemnification for civil liabilities,
including liabilities under the Securities Act.

                      WHERE YOU CAN FIND MORE INFORMATION

  Adelphia files annual, quarterly and special reports, as well as proxy
statements and other information with the SEC.  You may read and copy any
document Adelphia files with the SEC at the SEC's Public Reference Room at 450
Fifth Street, N.W., Washington, D.C. 20549 or at its Regional Offices in
Chicago, Illinois or New York, New York.  You may obtain further information
about the operation of the Public Reference Room by calling the SEC at 1-800-
SEC-0330.  Adelphia's SEC filings are also available to the public over the
Internet at the SEC's web site at

                                       16
http://www.sec.gov, which contains reports, proxy statements and other
information regarding registrants like Adelphia that file electronically with
the SEC.

  This prospectus is part of a registration statement on Form S-8 filed by
Adelphia with the SEC under the Securities Act.  As permitted by SEC rules, this
prospectus does not contain all of the information included in the registration
statement and the accompanying exhibits filed with the SEC.  You may refer to
the registration statement and its exhibits for more information.

  The SEC allows Adelphia to "incorporate by reference" into this prospectus the
information it files with the SEC.  This means that Adelphia can disclose
important information to you by referring you to those documents.  The
information incorporated by reference is considered to be part of this
prospectus.  If Adelphia subsequently files updating or superseding information
in a document that is incorporated by reference into this prospectus, the
subsequent information will also become part of this prospectus and will
supersede the earlier information.

  Adelphia is incorporating by reference the following documents that it has
filed with the SEC:

 .  its Annual Report on Form 10-K for the year ended March 31, 1998, which
   incorporates, in Items 7 and 8 to such Form 10-K, portions of the Form 10-K
   for the fiscal year ended December 31, 1997 of Olympus Communications, L.P.
   and Olympus Capital Corporation, as amended by Adelphia's Form 10-K/A dated
   July 27, 1998;

 .  its Quarterly Reports on Form 10-Q for the quarters ended June 30, 1998,
   September 30, 1998 and December 31, 1998;

 .  its Current Reports on Form 8-K for the events dated June 29, 1998, July 2,
   1998, August 3, 1998, August 18, 1998, September 10, 1998, November 9, 1998,
   November 12, 1998, December 23, 1998, January 11, 1999, February 22, 1999,
   February 23, 1999, and March 5, 1999;

 .  its definitive proxy statement dated September 11, 1998 with respect to the
   Annual Meeting of Stockholders held on October 6, 1998; and

 .  the description of its Class A common stock contained in:

   .  Adelphia's registration statement filed with the SEC under Section 12 of
      the Exchange Act and subsequent amendments and reports filed to update
      such description; and

   .  Adelphia's registration statement on Form S-3 (File No. 333-74219).

Adelphia is also incorporating by reference into this prospectus:

   .  all of its future filings with the SEC under Sections 13(a), 13(c), 14 or
      15(d) of the Exchange Act until this offering has been completed; and

   .  all of its filings made by it under the Exchange Act after the date the
      registration statement to which this prospectus is a part was initially
      filed and prior to the effective date of that registration statement.

  You may obtain a copy of any of our filings which are incorporated by
reference, at no cost, by writing to or telephoning us at the following address:

                    Adelphia Communications Corporation
                    Main at Water Street
                    Coudersport, Pennsylvania  16915
                    Attention:  Investor Relations
                    Telephone:  (814) 274-9830

                                       17
You should rely only on the information provided in this prospectus or
incorporated by reference.  We have not authorized anyone to provide you with
different information.  You should not assume that the information in this
prospectus is accurate as of any date other than the date on the first page of
the prospectus.  Adelphia is not making this offer of securities in any state or
country in which the offer or sale is not permitted.

                                       18
INDEMNIFICATION

  Adelphia's Bylaws provide that Adelphia shall, to the full extent permitted by
the Delaware General Corporation Law, indemnify certain persons whom it has the
power to indemnify pursuant thereto, including officers and directors of
Adelphia. The Bylaws also authorize Adelphia to maintain insurance to cover such
liabilities.

  Insofar as indemnification for liabilities arising under the Securities Act
may be permitted to directors, officers and persons controlling Adelphia
pursuant to the foregoing provisions, Adelphia has been informed that in the
opinion of the Commission, such indemnification is against public policy as
expressed in the Securities Act and is therefore unenforceable.

                                    EXPERTS

  The consolidated financial statements of Adelphia and its subsidiaries as of
March 31, 1997 and 1998, and for each of the three years in the period ended
March 31, 1998, and the consolidated financial statements of Olympus and its
subsidiaries as of December 31, 1996 and 1997, and for each of the three years
in the period ended December 31, 1997, all incorporated in this prospectus by
reference from Adelphia's Annual Report on Form 10-K for the year ended March
31, 1998, have been audited by Deloitte & Touche LLP, independent auditors, as
stated in their reports, which are incorporated herein by reference, and have
been so incorporated in reliance upon the reports of such firm given upon their
authority as experts in accounting and auditing.

                                       19
PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

  This Registration Statement relates to the Adelphia Communications Corporation
1998 Long-Term Incentive Compensation Plan. Adelphia Communications Corporation
("Adelphia") is incorporated in the State of Delaware.

Item 3.   Incorporation of Documents by Reference

  The following documents filed with the SEC by Adelphia are incorporated herein
by reference:

  (a) The latest annual report of Adelphia filed on Form 10-K for the fiscal
year ended March 31, 1998;

  (b) All other reports, if any, filed pursuant to Section 13(a) or 15(d) of the
Exchange Act since the end of the fiscal year covered by Adelphia's report
referred to in (a) above; and

  (c) The description of Adelphia's Class A Common Stock, par value $.01 per
share, as set forth in (i) Adelphia's registration statement filed with the SEC
under Section 12 of the Exchange Act and amendments and reports filed to update
such description and (ii) Adelphia's Registration Statement on Form S-3 and
accompanying prospectus filed pursuant to Rule 424(b)(5) filed with the SEC on
August 13, 1998 (File Number 333-58749).

  All documents subsequently filed by the Registrant with the SEC pursuant to
Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act, prior to the filing of
a post-effective amendment to this Registration Statement, which indicate that
all securities offered have been sold or which deregister all securities then
remaining unsold shall be deemed to be incorporated by reference in this
Registration Statement and to be a part hereof from the date of filing of such
documents.

Item 4.   Description of Securities

  Not applicable.

Item 5.  Interests of Named Experts and Counsel

  Not applicable.

Item 6.  Indemnification of Directors and Officers

  Section 145 of the Delaware General Corporation Law (the "DGCL") empowers a
Delaware corporation to indemnify any persons who are, or are threatened to be
made, parties to any threatened, pending or completed legal action, suit or
proceeding, whether civil, criminal, administrative or investigative (other than
an action by or in the right of such corporation), by reason of the fact that
such person was an officer or director of such corporation, or is or was serving
at the request of such corporation as a director, officer, employee or agent of
another corporation or enterprise.  The indemnity may include expenses
(including attorneys' fees), judgments, fines and amounts paid in settlement
actually and reasonably incurred by such person in connection with such action,
suit or proceeding, provided that such officer or director acted in good faith
in a manner he or she reasonably believed to be in or not opposed to the
corporation's best interests, and, for criminal proceedings, had no reasonable
cause to believe his or her conduct was illegal.  A Delaware corporation may
indemnify officers and directors in an action by or in the right of the
corporation under the same conditions, except that no indemnification is
permitted without judicial approval if the officer or director is adjudged to be
liable to the corporation in the performance of his or her duty.  Where an
officer or director is successful on the merits or otherwise in the defense of
any action referred to above, the corporation must indemnify him or her against
the expenses which such officer or director actually and reasonably incurred.
Adelphia's Bylaws provide for the indemnification of directors, officers and
employees of Adelphia within the limitations of Section 145.

  In accordance with Section 102(b)(7) of the DGCL, Adelphia's Restated
Certificate of Incorporation provides that directors shall not be personally
liable for monetary damages for breaches of their fiduciary duty as directors,

                                       20
except for (i) breaches of their duty of loyalty to Adelphia or its
stockholders, (ii) acts or omissions not in good faith or which involve
intentional misconduct or knowing violations of law, (iii) certain transactions
under Section 174 of the DGCL (unlawful payment of dividends or unlawful stock
purchases or redemptions), or (iv) transactions from which a director derives an
improper personal benefit.  The effect of the provision is to eliminate the
personal liability of directors for monetary damages for actions involving a
breach of their fiduciary duty of care, including any actions involving gross
negligence.

Item 7.  Exemption From Registration Claimed

  Not applicable.

Item 8.  Exhibits

  The following is a list of exhibits filed as part of this Registration
Statement, which are incorporated herein:
Exhibit No.    Reference
-------------  ---------
4.01  Certificate of Incorporation of Adelphia           Incorporated herein by reference is Exhibit 3.01
               Communications Corporation                         to Registrant's Current Report on Form 8-K dated
                                                                  July 24, 1997.  (File No. 0-16014)

         4.02  Bylaws of Adelphia Communications Corporation      Incorporated herein by reference is Exhibit 3.02
                                                                  to Registrant's Annual Report on Form 10-K for the
                                                                  fiscal year ended March 31, 1994.  (File No. 0-16014)

         4.03  Adelphia Communications Corporation 1998           Incorporated herein by reference is Exhibit A to
               Long-Term Incentive Compensation Plan              Registrant's Proxy Statement for the Annual
                                                                  Meeting of Stockholders held on October 6, 1998.
                                                                  (File No. 0-16014)

         5.01  Opinion of Buchanan Ingersoll Professional         Filed herewith.
               Corporation

        23.01  Consent of Deloitte & Touche LLP                   Filed herewith.

        23.02  Consent of Buchanan Ingersoll Professional         Contained in opinion filed as Exhibit 5.01.
               Corporation

        24.01  Power of Attorney                                  Contained on signature page.
Item 9.  Undertakings

  (a) The undersigned Registrant hereby undertakes:

  (1) To file, during any period in which offers or sales are being made, a
post-effective amendment to this Registration Statement:

     (i)   to include any prospectus required by Section 10(a)(3) of the
           Securities Act;

     (ii)  to reflect in the prospectus any facts or events, arising after the
           effective date of the Registration Statement (or the most recent
           post-effective amendment thereof) which, individually or in the
           aggregate, represent a fundamental change in the information set
           forth in the Registration Statement; and

                                       21
(iii) to include any material information with respect to the plan of
           distribution not previously disclosed in this Registration Statement
           or any material change to such information in this Registration
           Statement;

provided however, that subclauses (a)(1)(i) and (a)(1)(ii) do not apply if the
information required to be included in a post-effective amendment by the
foregoing clause is contained in periodic reports filed by Adelphia pursuant to
Section 13 or Section 15(d) of the Exchange Act that are incorporated by
reference in the Registration Statement;

  (2) That, for the purpose of determining any liability under the Securities
Act, each such post-effective amendment 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; and

  (3) To remove from registration by means of a post-effective amendment any of
the securities being registered which remain unsold at the termination of the
offering.

  (b)  Filings Incorporating Subsequent Exchange Act Documents by Reference.

  The undersigned Registrant hereby undertakes that, for purposes of determining
any liability under the Securities Act of 1933, each filing of the Registrant's
annual report pursuant to Section 13(a) or Section 15(d) of the Exchange Act
(and, where applicable, each filing of an employee benefit plan's annual report
pursuant to Section 15(d) of the Exchange Act) that is incorporated by reference
in this Registration Statement 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.

  (c) Request for Acceleration of Effective Date.

  Insofar as indemnification for liabilities arising under the Securities Act
may be permitted to directors, officers and controlling persons of Adelphia
pursuant to the provisions described in Item 6 of this Registration Statement,
or 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 of 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.

                                       22
SIGNATURES

  Pursuant to the requirements of the Securities Act, the Registrant certifies
that it has reasonable grounds to believe that it meets all of the requirements
for filing on Form S-8 and has duly caused this registration statement to be
signed on its behalf by the undersigned, thereunto duly authorized, in the City
of Coudersport, Commonwealth of Pennsylvania, on the 6th day of April, 1999.

                                 ADELPHIA COMMUNICATIONS CORPORATION

                                 By: /s/ Timothy J. Rigas
                                     --------------------
                                     Timothy J. Rigas
                                     Executive Vice President, Chief Accounting
                                     Officer, Chief Financial Officer and
                                     Treasurer

                               POWER OF ATTORNEY

  KNOW ALL MEN BY THE PRESENTS that each person whose signature appears below
constitutes and appoints John J. Rigas, Michael J. Rigas, Timothy Rigas, James
P. Rigas and Daniel R. Milliard, and each of them, such person's true and lawful
attorneys-in-fact and agents, with full power of substitution and revocation,
for such person and in such person's name, place and stead, in any and all
amendments (including post-effective amendments to this Registration Statement)
and to file the same with all exhibits thereto, and other documents in
connection therewith, with the Securities and Exchange Commission, granting unto
said attorneys-in-fact and agents, and each of them, full power and authority to
do and perform each and every act and thing requisite and necessary to be done,
as fully to all intents and purposes as such person might or could do in person,
hereby ratifying and confirming all that said attorneys-in-fact and agents or
any of them, or their or his substitute or substitutes, may lawfully do or cause
to be done by virtue hereof.

  Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed by the following persons in the capacities and on the
dates indicated.
SIGNATURE                                      TITLE                                DATE
/s/ John J. Rigas               Chairman, President and Chief Executive Officer           April 6, 1999
------------------------------ 
John J. Rigas

/s/ Michael J. Rigas            Executive Vice President and Director                     April 6, 1999
------------------------------ 
Michael J. Rigas

/s/ Timothy J. Rigas            Executive Vice President, Chief Accounting Officer,       April 6, 1999
------------------------------  Treasurer, Chief Financial Officer and Director
Timothy J. Rigas               

/s/ James P. Rigas              Executive Vice President and Director                     April 6, 1999
------------------------------ 
James P. Rigas

/s/ Daniel R. Milliard          Senior Vice President, Secretary and Director             April 6, 1999
------------------------------ 
Daniel R. Milliard

                                Director                                                  April __, 1999
------------------------------
Dennis P. Coyle

                                Director                                                  April __, 1999
------------------------------ 
Pete J. Metros

                                Director                                                  April __, 1999
------------------------------ 
Perry S. Patterson
23
EXHIBIT INDEX
                                 -------------
Exhibit No.                                                Description
4.01  Certificate of Incorporation of Adelphia           Incorporated herein by reference is Exhibit 3.01
               Communications Corporation                         to the Registrant's Current Report on Form 8-K
                                                                  dated July 24, 1997.  (File No. 0-16014)

         4.02  Bylaws of Adelphia Communications Corporation      Incorporated herein by reference is Exhibit 3.02
                                                                  to Registrant's Annual Report on Form 10-K for
                                                                  the fiscal year ended March 31, 1994.  (File No. 0-16014)

         4.03  Adelphia Communications Corporation 1998           Incorporated herein by reference is Exhibit A to
               Long-Term Incentive Compensation Plan              Registrant's Proxy Statement for the Annual
                                                                  Meeting of Stockholders held on October 6, 1998.
                                                                  (File No. 0-16014)

         5.01  Opinion of Buchanan Ingersoll Professional         Filed herewith.
               Corporation

        23.01  Consent of Deloitte & Touche LLP                   Filed herewith.

        23.02  Consent of Buchanan Ingersoll Professional         Contained in opinion filed as Exhibit 5.01.
               Corporation

        24.01  Power of Attorney                                  Contained on signature page.
24