<PAGE>
 
   As filed with the Securities and Exchange Commission on December 23, 1996
                                                            Registration No. 33-
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, DC  20549
                             ---------------------
                                    FORM S-8
                             REGISTRATION STATEMENT
                                     Under
                           THE SECURITIES ACT OF 1933
                             ---------------------

                            RHONE-POULENC RORER INC.
             (Exact name of registrant as specified in its charter)
     Pennsylvania                                23-1699163
(State or other jurisdiction of            (I.R.S. EmployerIdentification No.)
 incorporation or organization)

    500 Arcola Road
    Collegeville, PA                                        19426-0107
(Address of principal executive offices)                    (Zip Code)


                     CENTEON L.L.C. EMPLOYEE SAVINGS PLAN
                           (Full title of the plan)

                           RICHARD T. COLLIER, ESQ.
                           Rhone-Poulenc Rorer Inc.
                                500 Arcola Road
                          Collegeville, PA  19426-0107
                    (Name and address of agent for service)
                                 (610) 454-8000
         (Telephone number, including area code, of agent for service)
                            -----------------------
                         Copy of all communications to:
                            JAMES W. JENNINGS, ESQ.
                          Morgan, Lewis & Bockius LLP
                             2000 One Logan Square
                            Philadelphia, PA  19103
                                 (215) 963-5726

                        CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
--------------------------------------------------------------------------------------------
 Title of securities   Amount to be  Proposed maximum    Proposed maximum      Amount of
  to be registered      registered    offering price        aggregate       registration fee
                                       per share (1)    offering price (1)
--------------------------------------------------------------------------------------------
<S>                    <C>           <C>                <C>                 <C>
Common Stock,                75,000           $74.813          $5,610,975             $1,701
 without par value
--------------------------------------------------------------------------------------------
</TABLE>

(1)  Estimated pursuant to paragraphs (c) and (h) of Rule 457 solely for the
     purpose of calculating the registration fee, based upon the average of the
     high and low sales prices of shares of Common Stock on December 18, 1996,
     as reported on the New York Stock Exchange.

(2)  Pursuant to Rule 416(c) under the Securities Act of 1933, this
     Registration Statement also covers an indeterminate amount of interests to
     be offered or sold pursuant to the Centeon L.L.C. Employee Savings Plan.
<PAGE>
 
               This Registration Statement on Form S-8 (the "Registration
     Statement") filed by Rhone-Poulenc Rorer Inc. (the "Registrant") relates to
     75,000 shares (the "Shares") of the Company's Common Stock, without par
     value (the "Common Stock"), and an indeterminate number of interests
     issuable pursuant to the Centeon L.L.C. Employee Savings Plan (the "Plan").

                                    PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

     Item 3.  Incorporation of Documents by Reference.
              --------------------------------------- 

               The following documents, as filed by the Registrant with the
     Securities and Exchange Commission (the "Commission"), are incorporated by
     reference in this Registration Statement:

                    (a)  Annual Report on Form 10-K, filed with the Commission 
     on March 18, 1996 for the fiscal year ended December 31, 1995;

                    (b)  Quarterly Report on Form 10-Q filed with the 
     Commission on May 10, 1996 for the quarter ended March 31, 1996;

                    (c)  Quarterly Report on Form 10-Q filed on August 13, 1996 
     for the quarter ended June 30, 1996;

                    (d)  Quarterly Report on Form 10-Q filed on November 6, 
     1996 for the quarter ended September 30, 1996;

                    (e)  Proxy Statement for the Annual Meeting of 
     Stockholders held on May 3, 1996; and

                    (f)  The descriptions of the Common Stock of the 
     Registrant set forth in the Registrant's Registration Statements pursuant
     to Section 12 of the Exchange Act, and any amendment or report filed for
     the purpose of updating such description.

               In addition, the Report on Form 11-K for the nine month period
     ended September 30, 1996 with respect to the Plan, filed with the
     Commission, is incorporated by reference in this Registration Statement.

               All reports and other documents filed by the Registrant and the
     Plan pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities
     Exchange Act of 1934, after the date of this registration statement and
     prior to the filing of a post-effective amendment that indicates that all
     securities offered hereby have been sold or that deregisters all securities
     then remaining unsold, shall be deemed to be incorporated by reference
     herein and to be part hereof from the date of filing of such documents.

               Any statement contained in a document incorporated by reference
     herein shall be deemed to be modified or superseded for purposes hereof to
     the extent that a statement contained herein (or in any other subsequently
     filed document that is also incorporated by reference herein) modifies or
     supersedes such statement. Any such statement so modified or superseded
     shall not be deemed, except as so modified or superseded, to constitute a
     part hereof.

     Item 4.  Description of Securities.
              ------------------------- 

                 Not applicable.

                                       1
<PAGE>
 
     Item 5.  Interests of Named Experts and Counsel.
              -------------------------------------- 

               The consolidated financial statements of the Registrant and its
     subsidiaries included in the Registrant's Report on Form 10-K for the
     fiscal year ending December 31, 1995 and incorporated by reference in this
     registration statement have been audited by Coopers & Lybrand LLP,
     independent accountants, as set forth in their report contained therein.
     Such financial statements are, and audited annual financial statements to
     be included in subsequently filed documents will be, incorporated herein in
     reliance upon the reports of Coopers & Lybrand LLP pertaining to such
     financial statements (to the extent covered by consents filed with the
     Securities and Exchange Commission) given upon the authority of such firm
     as experts in accounting and auditing.

               The financial statements incorporated in this Registration
     Statement by reference to the Report of the Savings Plan on Form 11-K for
     the nine month period ended September 30, 1996, have been audited by
     Coopers & Lybrand LLP, independent accountants, as set forth in their
     report contained therein.  Such financial statements are, and audited
     annual financial statements to be included in subsequently filed documents
     will be, incorporated herein in reliance upon the reports of Coopers &
     Lybrand LLP pertaining to such financial statements (to the extent covered
     by consents filed with the Securities and Exchange Commission) given upon
     the authority of such firm as experts in accounting and auditing.

     Item 6.  Indemnification of Directors and Officers.
              ----------------------------------------- 

               Section 1741 of the Pennsylvania Business Corporation Law (the
     "PBCL") provides the Company the power to indemnify any officer or director
     acting in his or her capacity as a representative of the Company who was or
     is a party or is threatened to be made a party to any action or proceeding
     against expenses, judgments, penalties, fines and amounts paid in
     settlement in connection with such action or proceeding whether the action
     was instituted by a third party or arose by or in the right of the Company.
     Generally, the only limitation on the ability of the Company to indemnify
     its officers and directors is if the act violates a criminal statute or if
     the act or failure to act is finally determined by a court to have
     constituted willful misconduct or recklessness.

               The Bylaws of the Registrant provide that the Registrant shall
     indemnify any and all directors and officers of the Registrant and any
     other person designated as an "indemnified representative" by the board of
     directors of the Registrant (which may, but need not, include any person
     serving at the request of the Registrant, as a director, officer, fiduciary
     or trustee of another corporation, partnership, joint venture, trust,
     employee benefit plan or other entity or enterprise) (each, an "indemnified
     representative") against any liability incurred in connection with any
     threatened, pending or completed action, suit, appeal or other proceeding
     of any nature, whether civil, criminal, administrative or investigative,
     whether formal or informal, and whether brought by or in the right of the
     Registrant, a class of its security holders or otherwise (each, a
     "Proceeding") in which the indemnified representative may be involved as a
     party or otherwise, by reason of the fact that such person is or was
     serving in an indemnified capacity, including without limitation
     liabilities resulting from any actual or alleged breach or neglect of duty,
     error, misstatement or misleading statement, negligence, gross negligence
     or act giving rise to strict or products liability, except where such
     indemnification is expressly prohibited by applicable law or where conduct
     of the indemnified representative has been determined (as provided in the
     Bylaws) to constitute willful misconduct or recklessness or unlawful self-
     dealing, sufficient in the circumstances to bar indemnification against
     liabilities arising from the conduct.  If an indemnified representative is
     entitled to indemnification in respect of a portion, but not all, of any
     liabilities to which such person may be subject, the Registrant shall
     indemnify such indemnified representative to the maximum extent for such
     portion of the liabilities.  The termination of a Proceeding by judgment,
     order, settlement, conviction or upon a plea of nolo contendre or its
     equivalent shall not, of itself, create a presumption that the indemnified
     representative is not entitled to indemnification.   The Bylaws provide for
     the advancement of expenses to an indemnified party upon receipt of an
     undertaking by the party to repay those amounts if it is finally determined
     that the indemnified party is not entitled to indemnification.

               An indemnified representative shall be deemed to have discharged
     such person's duty to the Registrant if he or she has relied in good faith
     on information, opinions, reports or statements, including financial
     statements and other financial data, in each case prepared or presented by
     any of the following:

                                       2
<PAGE>
 
               (1)  one or more officers or employees of the Registrant whom the
     indemnified representative reasonably believes to be reliable and competent
     with respect to the matter presented;

               (2)  legal counsel, public accountants or other persons as to
     matters that the indemnified representative reasonably believes are within
     the person's professional or expert competence; or

               (3)  a committee of the board of directors on which he or she
     does not serve as to matters within its area of designated authority, which
     committee he or she reasonably believes to merit confidence.

               The Bylaws authorize the Company to take steps to ensure that all
     persons entitled to indemnification are properly indemnified, including, if
     the board of directors so determines, purchasing and maintaining insurance.
     The Company currently maintains directors and officers insurance.


     Item 7.  Exemption from Registration Claimed.
              ----------------------------------- 

               Not applicable.


     Item 8.  Exhibits.
              -------- 

               The exhibits filed as part of this Registration Statement are as
     follows:

     Exhibit
     Number                     Exhibit
     ------                     -------

      5          Opinion re legality (Common Stock of Registrant) (1)

     23.1        Consent of Coopers & Lybrand LLP

     23.2        Consent of Richard T. Collier, Senior Vice President and
                 General Counsel of the Registrant   (included in Exhibit 5)

     24          Power of Attorney

     99          Centeon L.L.C. Employee Savings Plan

     (1)         In lieu of an opinion of counsel concerning compliance with the
                 requirements of the Employee Retirement Income Security Act of
                 1974 as amended ("ERISA") and an Internal Revenue Service
                 ("IRS") determination letter that the Plan is qualified under
                 Section 401 of the Internal Revenue Code of 1986, as amended,
                 the Registrant hereby undertakes to submit the Plan to the IRS
                 in a timely manner, and shall make all changes required by the
                 IRS, in order to qualify the Plan.

                                       3
<PAGE>
 
     Item 9.  Undertakings.
              ------------ 

                 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 to
     include any prospectus required by Section 10(a)(3) of the Securities Act
     of 1933;

                    (i)  To include any prospectus required by Section 10(a)(3)
     of the Securities Act of 1933;

                    (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

                    (iii)  To include any material information with respect to 
     the plan of distribution not previously disclosed in the registration
     statement or any material change to such information in the registration
     statement;

               Provided, however, that subparagraphs (a)(1)(i) and (a)(1)(ii) of
               --------  -------                                                
     this section do not apply if the information required to be included in a
     post-effective amendment by those subparagraphs is contained in periodic
     reports filed by the Registrant pursuant to Section 13 or Section 15(d) of
     the Securities Exchange Act of 1934 that are incorporated by reference in
     the registration statement.

               (2)  That, for the purpose of determining any liability under the
     Securities Act of 1933, 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.

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

               The undersigned Registrant hereby undertakes that, for the
     purpose 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 Securities Exchange Act of 1934 (and each filing of an
     employee benefit plan's annual report pursuant to Section 15(d) of the
     Securities Exchange Act of 1934) that is incorporated by reference in this
     registration statement shall be deemed to be a new registration statement
     relating to the securities offered herein and the offering of such
     securities at that time shall be deemed to be the initial bona fide
     offering thereof.

               Insofar as indemnification for liabilities arising under the
     Securities Act of 1933 may be permitted to directors, officers and
     controlling persons of the Registrant pursuant to the foregoing provisions,
     or otherwise, the Registrant has been advised that in the opinion of the
     Securities and Exchange Commission such indemnification is against public
     policy as expressed in the Act and is, therefore, unenforceable.  In the
     event that a claim for indemnification against such liabilities (other than
     the payment by the Registrant of expenses incurred or paid by a director,
     officer or controlling person of the Registrant in the successful defense
     of any action, suit or proceeding) is asserted by such director, officer or
     controlling person in connection with the securities being registered, the
     Registrant will, unless in the opinion of its counsel the matter has been
     settled by controlling precedent, submit to a court of appropriate
     jurisdiction the question whether such indemnification by it is against
     public policy as expressed in the Act and will be governed by the final
     adjudication of such issue.

                                       4
<PAGE>
 
                                   SIGNATURES

               The Registrant.  Pursuant to the requirements of the Securities
               --------------                                                 
     Act of 1933, 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 Collegeville, Pennsylvania,
     on the 20th day of December, 1996.

                                RHONE-POULENC RORER INC.


                                By:   /s/ Michel de Rosen
                                      -----------------------------------------
                                      MICHEL DE ROSEN
                                      President and Chief Executive Officer


               Pursuant to the requirements of the Securities Act 1933, this
     Registration Statement has been signed below by the following persons in
     the capacities and on the date indicated.
<TABLE>
<CAPTION>
 
 
           Signature                            Capacity                      Date
--------------------------------  ------------------------------------  -----------------
<S>                               <C>                                   <C>
/s/  Jean-Marc Bruel              Director                              December 20, 1996
--------------------------------
Jean-Marc Bruel
 
/s/ Robert E. Cawthorn*           Director                              December 20, 1996
--------------------------------
Robert E. Cawthorn
 
/s/ Michel de Rosen               Chairman and Chief Executive Officer  December 20, 1996
--------------------------------  Director
Michel de Rosen                   
 
--------------------------------  Director
Charles-Henri Filippi
 
/s/ Dale F. Frey*                 Director                              December 20, 1996
--------------------------------
Dale F. Frey
 
/s/ Claude Helene*                Director                              December 20, 1996
--------------------------------
Claude Helene
 
--------------------------------  Director
Michael H. Jordan
 
/s/ Manfred E. Karobath, M.D.*    Director                              December 20, 1996
--------------------------------
Manfred E. Karobath, M.D.
 
/s/ Igor Landau*                  Director                              December 20, 1996
--------------------------------
Igor Landau
 
/s/ Patrick Langlois              Executive Vice President and          December 20, 1996
--------------------------------  Chief Financial Officer
Patrick Langlois
 
/s/ Philippe Maitre               Vice President and Controller         December 20, 1996
--------------------------------  (Principal Accounting Officer)
Philippe Maitre
 
</TABLE>

                                       5
<PAGE>
 
<TABLE>
           Signature                            Capacity                      Date
--------------------------------  ------------------------------------  -----------------
<S>                               <C>                                   <C>
/s/ Peter J. Neff*
--------------------------------  Director                              December 20, 1996
Peter J. Neff
 
/s/ James S. Riepe*               Director                              December 20, 1996
--------------------------------
James S. Riepe
 
--------------------------------  Director
Jean-Pierre Tirouflet
 
</TABLE>
     *  By:  /s/ Richard T. Collier
             -----------------------------
             RICHARD T. COLLIER
             Senior Vice President and
             General Counsel
             (Attorney-in-fact)



         The Plan.  Pursuant to the requirements of the Securities Act of 1933,
         --------                                                              
     of the Plan has duly caused this registration statement to be signed on its
     behalf by the undersigned, thereunto duly authorized, in King of Prussia,
     Pennsylvania on December 20, 1996.



                              CENTEON L.L.C.
                              EMPLOYEE SAVINGS PLAN

                              By: /s/ Richard A. Bierly
                                  -----------------------------------------
                              Name:  Richard A. Bierly
                              Title:    Vice President and Treasurer

                                       6
<PAGE>
 
                               INDEX TO EXHIBITS
<TABLE>
<CAPTION>
                                                                              Sequentially 
     Exhibit                                                                    Numbered
     Number                     Exhibit                                           Page
     ------                     -------                                           ----
<S>              <C>                                                          <C>
      5          Opinion re legality (Common Stock of Registrant) (1)

     23.1        Consent of Coopers & Lybrand LLP

     23.2        Consent of Richard T. Collier, Senior Vice President and
                 General Counsel of the Registrant (included in Exhibit 5)

     24          Power of Attorney

     99          Centeon L.L.C. Employee Savings Plan

     (1)         In lieu of an opinion of counsel concerning compliance
                 with the requirements of the Employee Retirement Income
                 Security Act of 1974 as amended ("ERISA") and an Internal
                 Revenue Service ("IRS") determination letter that the
                 Plan is qualified under Section 401 of the Internal Revenue
                 Code of 1986, as amended, the Registrant hereby undertakes
                 to submit the Plan to the IRS in a timely manner, and shall
                 make all changes required by the IRS, in order to qualify
                 the Plan.
</TABLE>
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 24557}]
{"company-data": {"conformed-name": "RHONE POULENC RORER INC", "cik": "0000217028", "assigned-sic": "2834", "irs-number": "231699163", "state-of-incorporation": "PA", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-18703", "film-number": "96685520"}, "business-address": {"street1": "500 ARCOLA RD", "street2": "P O BOX 1200 M/S 5B14", "city": "COLLEGEVILLE", "state": "PA", "zip": "19426-0107", "phone": "6104548000"}, "former-company": [{"former-conformed-name": "RORER GROUP INC", "date-changed": "19900731"}, {"former-conformed-name": "RORER AMCHEM INC", "date-changed": "19770604"}]}
As filed with the Securities and Exchange Commission on December 23, 1996
                                                            Registration No. 33-
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, DC  20549
                             ---------------------
                                    FORM S-8
                             REGISTRATION STATEMENT
                                     Under
                           THE SECURITIES ACT OF 1933
                             ---------------------

                            RHONE-POULENC RORER INC.
             (Exact name of registrant as specified in its charter)
     Pennsylvania                                23-1699163
(State or other jurisdiction of            (I.R.S. EmployerIdentification No.)
 incorporation or organization)

    500 Arcola Road
    Collegeville, PA                                        19426-0107
(Address of principal executive offices)                    (Zip Code)

                     CENTEON L.L.C. EMPLOYEE SAVINGS PLAN
                           (Full title of the plan)

                           RICHARD T. COLLIER, ESQ.
                           Rhone-Poulenc Rorer Inc.
                                500 Arcola Road
                          Collegeville, PA  19426-0107
                    (Name and address of agent for service)
                                 (610) 454-8000
         (Telephone number, including area code, of agent for service)
                            -----------------------
                         Copy of all communications to:
                            JAMES W. JENNINGS, ESQ.
                          Morgan, Lewis & Bockius LLP
                             2000 One Logan Square
                            Philadelphia, PA  19103
                                 (215) 963-5726

                        CALCULATION OF REGISTRATION FEE
--------------------------------------------------------------------------------------------
 Title of securities   Amount to be  Proposed maximum    Proposed maximum      Amount of
  to be registered      registered    offering price        aggregate       registration fee
                                       per share (1)    offering price (1)
--------------------------------------------------------------------------------------------
Common Stock,                75,000           $74.813          $5,610,975             $1,701
 without par value
--------------------------------------------------------------------------------------------
(1)  Estimated pursuant to paragraphs (c) and (h) of Rule 457 solely for the
     purpose of calculating the registration fee, based upon the average of the
     high and low sales prices of shares of Common Stock on December 18, 1996,
     as reported on the New York Stock Exchange.

(2)  Pursuant to Rule 416(c) under the Securities Act of 1933, this
     Registration Statement also covers an indeterminate amount of interests to
     be offered or sold pursuant to the Centeon L.L.C. Employee Savings Plan.
This Registration Statement on Form S-8 (the "Registration
     Statement") filed by Rhone-Poulenc Rorer Inc. (the "Registrant") relates to
     75,000 shares (the "Shares") of the Company's Common Stock, without par
     value (the "Common Stock"), and an indeterminate number of interests
     issuable pursuant to the Centeon L.L.C. Employee Savings Plan (the "Plan").

                                    PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

     Item 3.  Incorporation of Documents by Reference.
              --------------------------------------- 

               The following documents, as filed by the Registrant with the
     Securities and Exchange Commission (the "Commission"), are incorporated by
     reference in this Registration Statement:

                    (a)  Annual Report on Form 10-K, filed with the Commission 
     on March 18, 1996 for the fiscal year ended December 31, 1995;

                    (b)  Quarterly Report on Form 10-Q filed with the 
     Commission on May 10, 1996 for the quarter ended March 31, 1996;

                    (c)  Quarterly Report on Form 10-Q filed on August 13, 1996 
     for the quarter ended June 30, 1996;

                    (d)  Quarterly Report on Form 10-Q filed on November 6, 
     1996 for the quarter ended September 30, 1996;

                    (e)  Proxy Statement for the Annual Meeting of 
     Stockholders held on May 3, 1996; and

                    (f)  The descriptions of the Common Stock of the 
     Registrant set forth in the Registrant's Registration Statements pursuant
     to Section 12 of the Exchange Act, and any amendment or report filed for
     the purpose of updating such description.

               In addition, the Report on Form 11-K for the nine month period
     ended September 30, 1996 with respect to the Plan, filed with the
     Commission, is incorporated by reference in this Registration Statement.

               All reports and other documents filed by the Registrant and the
     Plan pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities
     Exchange Act of 1934, after the date of this registration statement and
     prior to the filing of a post-effective amendment that indicates that all
     securities offered hereby have been sold or that deregisters all securities
     then remaining unsold, shall be deemed to be incorporated by reference
     herein and to be part hereof from the date of filing of such documents.

               Any statement contained in a document incorporated by reference
     herein shall be deemed to be modified or superseded for purposes hereof to
     the extent that a statement contained herein (or in any other subsequently
     filed document that is also incorporated by reference herein) modifies or
     supersedes such statement. Any such statement so modified or superseded
     shall not be deemed, except as so modified or superseded, to constitute a
     part hereof.

     Item 4.  Description of Securities.
              ------------------------- 

                 Not applicable.

                                       1
Item 5.  Interests of Named Experts and Counsel.
              -------------------------------------- 

               The consolidated financial statements of the Registrant and its
     subsidiaries included in the Registrant's Report on Form 10-K for the
     fiscal year ending December 31, 1995 and incorporated by reference in this
     registration statement have been audited by Coopers & Lybrand LLP,
     independent accountants, as set forth in their report contained therein.
     Such financial statements are, and audited annual financial statements to
     be included in subsequently filed documents will be, incorporated herein in
     reliance upon the reports of Coopers & Lybrand LLP pertaining to such
     financial statements (to the extent covered by consents filed with the
     Securities and Exchange Commission) given upon the authority of such firm
     as experts in accounting and auditing.

               The financial statements incorporated in this Registration
     Statement by reference to the Report of the Savings Plan on Form 11-K for
     the nine month period ended September 30, 1996, have been audited by
     Coopers & Lybrand LLP, independent accountants, as set forth in their
     report contained therein.  Such financial statements are, and audited
     annual financial statements to be included in subsequently filed documents
     will be, incorporated herein in reliance upon the reports of Coopers &
     Lybrand LLP pertaining to such financial statements (to the extent covered
     by consents filed with the Securities and Exchange Commission) given upon
     the authority of such firm as experts in accounting and auditing.

     Item 6.  Indemnification of Directors and Officers.
              ----------------------------------------- 

               Section 1741 of the Pennsylvania Business Corporation Law (the
     "PBCL") provides the Company the power to indemnify any officer or director
     acting in his or her capacity as a representative of the Company who was or
     is a party or is threatened to be made a party to any action or proceeding
     against expenses, judgments, penalties, fines and amounts paid in
     settlement in connection with such action or proceeding whether the action
     was instituted by a third party or arose by or in the right of the Company.
     Generally, the only limitation on the ability of the Company to indemnify
     its officers and directors is if the act violates a criminal statute or if
     the act or failure to act is finally determined by a court to have
     constituted willful misconduct or recklessness.

               The Bylaws of the Registrant provide that the Registrant shall
     indemnify any and all directors and officers of the Registrant and any
     other person designated as an "indemnified representative" by the board of
     directors of the Registrant (which may, but need not, include any person
     serving at the request of the Registrant, as a director, officer, fiduciary
     or trustee of another corporation, partnership, joint venture, trust,
     employee benefit plan or other entity or enterprise) (each, an "indemnified
     representative") against any liability incurred in connection with any
     threatened, pending or completed action, suit, appeal or other proceeding
     of any nature, whether civil, criminal, administrative or investigative,
     whether formal or informal, and whether brought by or in the right of the
     Registrant, a class of its security holders or otherwise (each, a
     "Proceeding") in which the indemnified representative may be involved as a
     party or otherwise, by reason of the fact that such person is or was
     serving in an indemnified capacity, including without limitation
     liabilities resulting from any actual or alleged breach or neglect of duty,
     error, misstatement or misleading statement, negligence, gross negligence
     or act giving rise to strict or products liability, except where such
     indemnification is expressly prohibited by applicable law or where conduct
     of the indemnified representative has been determined (as provided in the
     Bylaws) to constitute willful misconduct or recklessness or unlawful self-
     dealing, sufficient in the circumstances to bar indemnification against
     liabilities arising from the conduct.  If an indemnified representative is
     entitled to indemnification in respect of a portion, but not all, of any
     liabilities to which such person may be subject, the Registrant shall
     indemnify such indemnified representative to the maximum extent for such
     portion of the liabilities.  The termination of a Proceeding by judgment,
     order, settlement, conviction or upon a plea of nolo contendre or its
     equivalent shall not, of itself, create a presumption that the indemnified
     representative is not entitled to indemnification.   The Bylaws provide for
     the advancement of expenses to an indemnified party upon receipt of an
     undertaking by the party to repay those amounts if it is finally determined
     that the indemnified party is not entitled to indemnification.

               An indemnified representative shall be deemed to have discharged
     such person's duty to the Registrant if he or she has relied in good faith
     on information, opinions, reports or statements, including financial
     statements and other financial data, in each case prepared or presented by
     any of the following:

                                       2
(1)  one or more officers or employees of the Registrant whom the
     indemnified representative reasonably believes to be reliable and competent
     with respect to the matter presented;

               (2)  legal counsel, public accountants or other persons as to
     matters that the indemnified representative reasonably believes are within
     the person's professional or expert competence; or

               (3)  a committee of the board of directors on which he or she
     does not serve as to matters within its area of designated authority, which
     committee he or she reasonably believes to merit confidence.

               The Bylaws authorize the Company to take steps to ensure that all
     persons entitled to indemnification are properly indemnified, including, if
     the board of directors so determines, purchasing and maintaining insurance.
     The Company currently maintains directors and officers insurance.

     Item 7.  Exemption from Registration Claimed.
              ----------------------------------- 

               Not applicable.

     Item 8.  Exhibits.
              -------- 

               The exhibits filed as part of this Registration Statement are as
     follows:

     Exhibit
     Number                     Exhibit
     ------                     -------

      5          Opinion re legality (Common Stock of Registrant) (1)

     23.1        Consent of Coopers & Lybrand LLP

     23.2        Consent of Richard T. Collier, Senior Vice President and
                 General Counsel of the Registrant   (included in Exhibit 5)

     24          Power of Attorney

     99          Centeon L.L.C. Employee Savings Plan

     (1)         In lieu of an opinion of counsel concerning compliance with the
                 requirements of the Employee Retirement Income Security Act of
                 1974 as amended ("ERISA") and an Internal Revenue Service
                 ("IRS") determination letter that the Plan is qualified under
                 Section 401 of the Internal Revenue Code of 1986, as amended,
                 the Registrant hereby undertakes to submit the Plan to the IRS
                 in a timely manner, and shall make all changes required by the
                 IRS, in order to qualify the Plan.

                                       3
Item 9.  Undertakings.
              ------------ 

                 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 to
     include any prospectus required by Section 10(a)(3) of the Securities Act
     of 1933;

                    (i)  To include any prospectus required by Section 10(a)(3)
     of the Securities Act of 1933;

                    (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

                    (iii)  To include any material information with respect to 
     the plan of distribution not previously disclosed in the registration
     statement or any material change to such information in the registration
     statement;

               Provided, however, that subparagraphs (a)(1)(i) and (a)(1)(ii) of
               --------  -------                                                
     this section do not apply if the information required to be included in a
     post-effective amendment by those subparagraphs is contained in periodic
     reports filed by the Registrant pursuant to Section 13 or Section 15(d) of
     the Securities Exchange Act of 1934 that are incorporated by reference in
     the registration statement.

               (2)  That, for the purpose of determining any liability under the
     Securities Act of 1933, 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.

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

               The undersigned Registrant hereby undertakes that, for the
     purpose 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 Securities Exchange Act of 1934 (and each filing of an
     employee benefit plan's annual report pursuant to Section 15(d) of the
     Securities Exchange Act of 1934) that is incorporated by reference in this
     registration statement shall be deemed to be a new registration statement
     relating to the securities offered herein and the offering of such
     securities at that time shall be deemed to be the initial bona fide
     offering thereof.

               Insofar as indemnification for liabilities arising under the
     Securities Act of 1933 may be permitted to directors, officers and
     controlling persons of the Registrant pursuant to the foregoing provisions,
     or otherwise, the Registrant has been advised that in the opinion of the
     Securities and Exchange Commission such indemnification is against public
     policy as expressed in the Act and is, therefore, unenforceable.  In the
     event that a claim for indemnification against such liabilities (other than
     the payment by the Registrant of expenses incurred or paid by a director,
     officer or controlling person of the Registrant in the successful defense
     of any action, suit or proceeding) is asserted by such director, officer or
     controlling person in connection with the securities being registered, the
     Registrant will, unless in the opinion of its counsel the matter has been
     settled by controlling precedent, submit to a court of appropriate
     jurisdiction the question whether such indemnification by it is against
     public policy as expressed in the Act and will be governed by the final
     adjudication of such issue.

                                       4
SIGNATURES

               The Registrant.  Pursuant to the requirements of the Securities
               --------------                                                 
     Act of 1933, 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 Collegeville, Pennsylvania,
     on the 20th day of December, 1996.

                                RHONE-POULENC RORER INC.

                                By:   /s/ Michel de Rosen
                                      -----------------------------------------
                                      MICHEL DE ROSEN
                                      President and Chief Executive Officer

               Pursuant to the requirements of the Securities Act 1933, this
     Registration Statement has been signed below by the following persons in
     the capacities and on the date indicated.
Signature                            Capacity                      Date
--------------------------------  ------------------------------------  -----------------
/s/  Jean-Marc Bruel              Director                              December 20, 1996
--------------------------------
Jean-Marc Bruel
 
/s/ Robert E. Cawthorn*           Director                              December 20, 1996
--------------------------------
Robert E. Cawthorn
 
/s/ Michel de Rosen               Chairman and Chief Executive Officer  December 20, 1996
--------------------------------  Director
Michel de Rosen                   
 
--------------------------------  Director
Charles-Henri Filippi
 
/s/ Dale F. Frey*                 Director                              December 20, 1996
--------------------------------
Dale F. Frey
 
/s/ Claude Helene*                Director                              December 20, 1996
--------------------------------
Claude Helene
 
--------------------------------  Director
Michael H. Jordan
 
/s/ Manfred E. Karobath, M.D.*    Director                              December 20, 1996
--------------------------------
Manfred E. Karobath, M.D.
 
/s/ Igor Landau*                  Director                              December 20, 1996
--------------------------------
Igor Landau
 
/s/ Patrick Langlois              Executive Vice President and          December 20, 1996
--------------------------------  Chief Financial Officer
Patrick Langlois
 
/s/ Philippe Maitre               Vice President and Controller         December 20, 1996
--------------------------------  (Principal Accounting Officer)
Philippe Maitre
5
Signature                            Capacity                      Date
--------------------------------  ------------------------------------  -----------------
/s/ Peter J. Neff*
--------------------------------  Director                              December 20, 1996
Peter J. Neff
 
/s/ James S. Riepe*               Director                              December 20, 1996
--------------------------------
James S. Riepe
 
--------------------------------  Director
Jean-Pierre Tirouflet
*  By:  /s/ Richard T. Collier
             -----------------------------
             RICHARD T. COLLIER
             Senior Vice President and
             General Counsel
             (Attorney-in-fact)

         The Plan.  Pursuant to the requirements of the Securities Act of 1933,
         --------                                                              
     of the Plan has duly caused this registration statement to be signed on its
     behalf by the undersigned, thereunto duly authorized, in King of Prussia,
     Pennsylvania on December 20, 1996.

                              CENTEON L.L.C.
                              EMPLOYEE SAVINGS PLAN

                              By: /s/ Richard A. Bierly
                                  -----------------------------------------
                              Name:  Richard A. Bierly
                              Title:    Vice President and Treasurer

                                       6
INDEX TO EXHIBITS
Sequentially 
     Exhibit                                                                    Numbered
     Number                     Exhibit                                           Page
     ------                     -------                                           ----
5          Opinion re legality (Common Stock of Registrant) (1)

     23.1        Consent of Coopers & Lybrand LLP

     23.2        Consent of Richard T. Collier, Senior Vice President and
                 General Counsel of the Registrant (included in Exhibit 5)

     24          Power of Attorney

     99          Centeon L.L.C. Employee Savings Plan

     (1)         In lieu of an opinion of counsel concerning compliance
                 with the requirements of the Employee Retirement Income
                 Security Act of 1974 as amended ("ERISA") and an Internal
                 Revenue Service ("IRS") determination letter that the
                 Plan is qualified under Section 401 of the Internal Revenue
                 Code of 1986, as amended, the Registrant hereby undertakes
                 to submit the Plan to the IRS in a timely manner, and shall
                 make all changes required by the IRS, in order to qualify
                 the Plan.