As filed with the Securities and Exchange Commission on April 23, 1998

                                          Registration Statement No. 333-
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                               450 5th Street N.W.
                             Washington, D.C. 20549

                                   ----------

                                    FORM S-8

                             REGISTRATION STATEMENT

                                      Under

                           THE SECURITIES ACT OF 1933

                                   ----------

                                   PFIZER INC.
             (Exact name of Registrant as specified in its charter)

        DELAWARE                                         13-5315170
(State of Incorporation)                              (I.R.S. Employer
                                                     Identification No.)

                              235 EAST 42ND STREET
                          NEW YORK, NEW YORK 10017-5755
                    (Address of Principal Executive Offices)

                                   ----------

                      PFIZER INC. STOCK AND INCENTIVE PLAN
                            (Full Title of the Plan)

                             MARGARET M. FORAN, ESQ.
                                   PFIZER INC.
                              235 EAST 42ND STREET
                          NEW YORK, NEW YORK 10017-5755
                    (Name and Address of Agent for Services)

                                 (212) 773-4802
                     (Telephone Number of Agent for Service)

                                   ----------

                         CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>
===========================================================================================================
                                                                                 Proposed
                                                                Proposed          Maximum
                                               Amount            Maximum         Aggregate      Amount of
       Title of Securities                      to be        Offering Price      Offering     Registration
        to be Registered                     Registered       Per Share(1)       Price(1)          Fee
-----------------------------------------------------------------------------------------------------------
<S>                                        <C>                 <C>            <C>              <C>                     
Common Stock, $.05 par value............   46,000,000 shs.     $102.84375     $4,730,812,500  $1,395,589.69
===========================================================================================================
</TABLE>

(1) Estimated to calculate the registration fee based on the average of the high
    and low  prices of Pfizer  Inc.  Common  Stock for New York  Stock  Exchange
    Composite  Transactions  on April 17,  1998,  as reported in The Wall Street
    Journal.

================================================================================

<PAGE>

                                    PART II.

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE

      The following are incorporated by reference:

      o     The  Annual  Report of Pfizer  Inc.  on Form 10-K for the year ended
            December 31, 1997,

      o     all other  reports  we filed  under  Sections  13(a) or 15(d) of the
            Securities Exchange Act of 1934,

      o     the  description of our common stock  contained in our  Registration
            Statement  filed under Section 12 of the Securities  Exchange Act of
            1934,

      o     and any amendment or report filed to update such description.

All documents later filed by us under Section 13(a), 13(c), 14, and 15(d) of the
Securities Exchange Act of 1934, before we file a post-effective  amendment that
indicates  all  securities  offered  have  been  sold or which  deregisters  all
securities  that have not been sold,  will be incorporated by reference and will
be a part of this filing from the date that document was filed.

ITEM 4. DESCRIPTION OF SECURITIES

      Not applicable.

ITEM 5. INTERESTS OF NAMED EXPERTS AND COUNSEL

      The validity of the  securities has been passed upon by Margaret M. Foran,
Esq.,  Senior  Corporate  Counsel and Assistant  Secretary for the Company.  Ms.
Foran  beneficially  owns  Common  Stock and options to  purchase  Common  Stock
granted under the Pfizer Inc. Stock and Incentive Plan.

ITEM 6. INDEMNIFICATION OF DIRECTORS AND OFFICERS

      Section  145  of  the  General  Corporation  Law  of  Delaware  permits  a
corporation  to  indemnify  any person who is or has been a  director,  officer,
employee  or  agent  of the  corporation  or who is or  has  been  serving  as a
director,  officer,  employee or agent of another  corporation,  organization or
enterprise at the request of the corporation, against all liability and expenses
(including,  but not limited to,  attorneys' fees and  disbursements and amounts
paid in  settlement  or in  satisfaction  of judgments or as fines or penalties)
incurred or paid in  connection  with any action,  suit or  proceeding,  whether
civil, criminal, administrative, investigative or otherwise, in which he/she may
be  involved  by reason of the fact that  he/she  served or is  serving in these
capacities,  if he/she  acted in good  faith and in a manner  he/she  reasonably
believed to be in or not opposed to the best interests of the  corporation  and,
with  respect  to any  criminal  action or  proceeding,  had no cause to believe
his/her conduct was unlawful. In the case of a claim, action, suit or proceeding
made or brought by or in the right of the  corporation  to procure a recovery or
judgment  in its favor,  the  corporation  shall not  indemnify  such  person in
respect of any claim,  issue or matter as to which such person has been adjudged
to be liable to the  corporation for negligence or misconduct in the performance
of his or her duty to the corporation, except for such expenses as the Court may
allow. Any such person who has been wholly successful on the merits or otherwise
with respect to any such claim,  action,  suit or  proceeding or with respect to
any claim, issue or matter therein, shall be indemnified as of right against all
expenses in connection therewith or resulting therefrom.

     Pursuant  to Article V,  Section 1 of its  By-Laws,  the  Registrant  shall
indemnify  directors and officers to the fullest extent  permitted by applicable
law as it presently exists or may hereinafter be amended. The Company is insured
against actions taken pursuant to its By-Laws and the directors and officers are
insured  directly at the Company's  expense  against such  liabilities for which
indemnification  is not made. The Company has entered into  agreements  with its
directors and certain of its officers  requiring  the Company to indemnify  such
persons to the fullest extent permitted by the Company's By-Laws.


                                      II-1

<PAGE>

ITEM 7. EXEMPTION FROM REGISTRATION CLAIMED

      Not Applicable.

ITEM 8. EXHIBITS

EXHIBIT

  5      --Opinion  and  Consent  of  Margaret M. Foran, Esq., Senior  Corporate
           Counsel and Assistant Secretary.

 23(b)   --Consent  of  KPMG  Peat  Marwick  LLP,  independent  certified public
           accountants.

ITEM 9. UNDERTAKINGS

      The Company 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 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)  which,  individually  or in  the
            aggregate,  represent a fundamental  change in the  information  set
            forth in the registration statement;

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

      provided,  however, that paragraphs (1)(i) and (1)(ii) do not apply if the
      registration  statement  is on Form  S-3 or Form  S-8 and the  information
      required to be included in a post-effective  amendment by those paragraphs
      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  purposes  of  determining  any  liability  under the
      Securities Act of 1933, each such post-effective  amendment shall be a new
      registration  statement  relating  to  the  securities  offered,  and  the
      offering  of such  securities  at that time will be viewed as the  initial
      bona fide offering.

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

            (4) 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 Securities  Exchange Act
      of 1934 that is  incorporated by reference in the  registration  statement
      will be a new registration  statement relating to the securities  offered,
      and the  offering of such  securities  at that time shall be viewed as the
      initial bona fide offering.

      Insofar as  indemnification  for liabilities  arising under the Securities
Act of 1933 may be permitted to directors,  officers and controlling  persons of
the registrant under 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
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.


                                      II-2
<PAGE>

                                   SIGNATURES

      Under the  requirements  of the Securities Act of 1933, the Registrant has
reasonable  grounds to believe that it meets all of the  requirements for filing
on Form S-8 and has  caused  this  Registration  Statement  to be  signed on its
behalf by the authorized  signer in The City of New York,  State of New York, on
the 23rd day of April, 1998.

                                    Pfizer Inc.
                                    (Registrant)

                                       By:    /s/ William C. Steere, Jr.
                                          --------------------------------------
                                                  William C. Steere, Jr.,
                                                 Chairman of the Board and
                                                  Chief Executive Officer
                                               (Principal Executive Officer)

      Under the  requirement of the Securities  Act of 1933,  this  Registration
Statement has been signed below by the following  persons in the  capacities and
on the dates indicated.

           Signature                       Title                    Date
           ---------                       -----                    ----

/s/ William C. Steere, Jr.                                                     
------------------------------   Chairman of the Board and        April 23, 1998
    William C. Steere, Jr.         Chief Executive Officer,       
                                                                  
                                 Director (Principal Executive    
                                   Officer)                       
  /s/ David L. Shedlarz                                                        
------------------------------   Senior Vice President and        April 23, 1998
      David L. Shedlarz            Chief Financial Officer        
                                   (Principal Financial Officer)  

   /s/ Herbert V. Ryan                                                          
------------------------------   Vice President and Controller    April 23, 1998
       Herbert V. Ryan             (Principal Accounting Officer) 

   /s/ Michael S. Brown                                                        
------------------------------   Director                         April 23, 1998
       Michael S. Brown                                           

   /s/ M. Anthony Burns                                                       
------------------------------   Director                         April 23, 1998
       M. Anthony Burns                                           

    /s/ W. Don Cornwell                                                        
------------------------------   Director                         April 23, 1998
        W. Don Cornwell                                           

   /s/ George B. Harvey                                                       
------------------------------   Director                         April 23, 1998
       George B. Harvey                                           


                                      II-3
<PAGE>

          Signature                       Title                        Date
          ---------                       -----                        ----

 /s/ Constance J. Horner
-----------------------------   Director                          April 23, 1998
     Constance J. Horner

/s/ Stanley O. Ikenberry
-----------------------------   Director                          April 23, 1998
    Stanley O. Ikenberry

   /s/ Harry P. Kamen
-----------------------------   Director                          April 23, 1998
       Harry P. Kamen

 /s/ Thomas G. Labrecque
-----------------------------   Director                          April 23, 1998
     Thomas G. Labrecque

    /s/ Dana G. Mead
-----------------------------   Director                          April 23, 1998
        Dana G. Mead

 /s/ Henry A. McKinnell
-----------------------------   Director                          April 23, 1998
     Henry A. McKinnell

   /s/ John F. Niblack
-----------------------------   Director                          April 23, 1998
       John F. Niblack

   /s/ Ruth J. Simmons
-----------------------------   Director                          April 23, 1998
       Ruth J. Simmons

  /s/ Jean-Paul Valles
-----------------------------   Director                          April 23, 1998
      Jean-Paul Valles


                                      II-4
<PAGE>


                                  EXHIBIT INDEX

EXHIBIT
-------

 5    Opinion and Consent of Margaret M. Foran, Esq., Senior Corporate Counsel 
      and Assistant Secretary

23(b) Consent of KPMG Peat Marwick LLP, independent certified public accountants
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 16200}]
{"company-data": {"conformed-name": "PFIZER INC", "cik": "0000078003", "assigned-sic": "2834", "irs-number": "135315170", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-50899", "film-number": "98600235"}, "business-address": {"street1": "235 E 42ND ST", "city": "NEW YORK", "state": "NY", "zip": "10017", "phone": "2125732323"}, "mail-address": {"street1": "235 E 42ND ST", "city": "NEW YORK", "state": "NY", "zip": "10017"}, "former-company": {"former-conformed-name": "PFIZER CHARLES & CO INC", "date-changed": "19710908"}}
As filed with the Securities and Exchange Commission on April 23, 1998

                                          Registration Statement No. 333-
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                               450 5th Street N.W.
                             Washington, D.C. 20549

                                   ----------

                                    FORM S-8

                             REGISTRATION STATEMENT

                                      Under

                           THE SECURITIES ACT OF 1933

                                   ----------

                                   PFIZER INC.
             (Exact name of Registrant as specified in its charter)

        DELAWARE                                         13-5315170
(State of Incorporation)                              (I.R.S. Employer
                                                     Identification No.)

                              235 EAST 42ND STREET
                          NEW YORK, NEW YORK 10017-5755
                    (Address of Principal Executive Offices)

                                   ----------

                      PFIZER INC. STOCK AND INCENTIVE PLAN
                            (Full Title of the Plan)

                             MARGARET M. FORAN, ESQ.
                                   PFIZER INC.
                              235 EAST 42ND STREET
                          NEW YORK, NEW YORK 10017-5755
                    (Name and Address of Agent for Services)

                                 (212) 773-4802
                     (Telephone Number of Agent for Service)

                                   ----------

                         CALCULATION OF REGISTRATION FEE
===========================================================================================================
                                                                                 Proposed
                                                                Proposed          Maximum
                                               Amount            Maximum         Aggregate      Amount of
       Title of Securities                      to be        Offering Price      Offering     Registration
        to be Registered                     Registered       Per Share(1)       Price(1)          Fee
-----------------------------------------------------------------------------------------------------------
Common Stock, $.05 par value............   46,000,000 shs.     $102.84375     $4,730,812,500  $1,395,589.69
===========================================================================================================
(1) Estimated to calculate the registration fee based on the average of the high
    and low  prices of Pfizer  Inc.  Common  Stock for New York  Stock  Exchange
    Composite  Transactions  on April 17,  1998,  as reported in The Wall Street
    Journal.

================================================================================
PART II.

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE

      The following are incorporated by reference:

      o     The  Annual  Report of Pfizer  Inc.  on Form 10-K for the year ended
            December 31, 1997,

      o     all other  reports  we filed  under  Sections  13(a) or 15(d) of the
            Securities Exchange Act of 1934,

      o     the  description of our common stock  contained in our  Registration
            Statement  filed under Section 12 of the Securities  Exchange Act of
            1934,

      o     and any amendment or report filed to update such description.

All documents later filed by us under Section 13(a), 13(c), 14, and 15(d) of the
Securities Exchange Act of 1934, before we file a post-effective  amendment that
indicates  all  securities  offered  have  been  sold or which  deregisters  all
securities  that have not been sold,  will be incorporated by reference and will
be a part of this filing from the date that document was filed.

ITEM 4. DESCRIPTION OF SECURITIES

      Not applicable.

ITEM 5. INTERESTS OF NAMED EXPERTS AND COUNSEL

      The validity of the  securities has been passed upon by Margaret M. Foran,
Esq.,  Senior  Corporate  Counsel and Assistant  Secretary for the Company.  Ms.
Foran  beneficially  owns  Common  Stock and options to  purchase  Common  Stock
granted under the Pfizer Inc. Stock and Incentive Plan.

ITEM 6. INDEMNIFICATION OF DIRECTORS AND OFFICERS

      Section  145  of  the  General  Corporation  Law  of  Delaware  permits  a
corporation  to  indemnify  any person who is or has been a  director,  officer,
employee  or  agent  of the  corporation  or who is or  has  been  serving  as a
director,  officer,  employee or agent of another  corporation,  organization or
enterprise at the request of the corporation, against all liability and expenses
(including,  but not limited to,  attorneys' fees and  disbursements and amounts
paid in  settlement  or in  satisfaction  of judgments or as fines or penalties)
incurred or paid in  connection  with any action,  suit or  proceeding,  whether
civil, criminal, administrative, investigative or otherwise, in which he/she may
be  involved  by reason of the fact that  he/she  served or is  serving in these
capacities,  if he/she  acted in good  faith and in a manner  he/she  reasonably
believed to be in or not opposed to the best interests of the  corporation  and,
with  respect  to any  criminal  action or  proceeding,  had no cause to believe
his/her conduct was unlawful. In the case of a claim, action, suit or proceeding
made or brought by or in the right of the  corporation  to procure a recovery or
judgment  in its favor,  the  corporation  shall not  indemnify  such  person in
respect of any claim,  issue or matter as to which such person has been adjudged
to be liable to the  corporation for negligence or misconduct in the performance
of his or her duty to the corporation, except for such expenses as the Court may
allow. Any such person who has been wholly successful on the merits or otherwise
with respect to any such claim,  action,  suit or  proceeding or with respect to
any claim, issue or matter therein, shall be indemnified as of right against all
expenses in connection therewith or resulting therefrom.

     Pursuant  to Article V,  Section 1 of its  By-Laws,  the  Registrant  shall
indemnify  directors and officers to the fullest extent  permitted by applicable
law as it presently exists or may hereinafter be amended. The Company is insured
against actions taken pursuant to its By-Laws and the directors and officers are
insured  directly at the Company's  expense  against such  liabilities for which
indemnification  is not made. The Company has entered into  agreements  with its
directors and certain of its officers  requiring  the Company to indemnify  such
persons to the fullest extent permitted by the Company's By-Laws.

                                      II-1
ITEM 7. EXEMPTION FROM REGISTRATION CLAIMED

      Not Applicable.

ITEM 8. EXHIBITS

EXHIBIT

  5      --Opinion  and  Consent  of  Margaret M. Foran, Esq., Senior  Corporate
           Counsel and Assistant Secretary.

 23(b)   --Consent  of  KPMG  Peat  Marwick  LLP,  independent  certified public
           accountants.

ITEM 9. UNDERTAKINGS

      The Company 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 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)  which,  individually  or in  the
            aggregate,  represent a fundamental  change in the  information  set
            forth in the registration statement;

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

      provided,  however, that paragraphs (1)(i) and (1)(ii) do not apply if the
      registration  statement  is on Form  S-3 or Form  S-8 and the  information
      required to be included in a post-effective  amendment by those paragraphs
      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  purposes  of  determining  any  liability  under the
      Securities Act of 1933, each such post-effective  amendment shall be a new
      registration  statement  relating  to  the  securities  offered,  and  the
      offering  of such  securities  at that time will be viewed as the  initial
      bona fide offering.

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

            (4) 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 Securities  Exchange Act
      of 1934 that is  incorporated by reference in the  registration  statement
      will be a new registration  statement relating to the securities  offered,
      and the  offering of such  securities  at that time shall be viewed as the
      initial bona fide offering.

      Insofar as  indemnification  for liabilities  arising under the Securities
Act of 1933 may be permitted to directors,  officers and controlling  persons of
the registrant under 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
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.

                                      II-2
SIGNATURES

      Under the  requirements  of the Securities Act of 1933, the Registrant has
reasonable  grounds to believe that it meets all of the  requirements for filing
on Form S-8 and has  caused  this  Registration  Statement  to be  signed on its
behalf by the authorized  signer in The City of New York,  State of New York, on
the 23rd day of April, 1998.

                                    Pfizer Inc.
                                    (Registrant)

                                       By:    /s/ William C. Steere, Jr.
                                          --------------------------------------
                                                  William C. Steere, Jr.,
                                                 Chairman of the Board and
                                                  Chief Executive Officer
                                               (Principal Executive Officer)

      Under the  requirement of the Securities  Act of 1933,  this  Registration
Statement has been signed below by the following  persons in the  capacities and
on the dates indicated.

           Signature                       Title                    Date
           ---------                       -----                    ----

/s/ William C. Steere, Jr.                                                     
------------------------------   Chairman of the Board and        April 23, 1998
    William C. Steere, Jr.         Chief Executive Officer,       
                                                                  
                                 Director (Principal Executive    
                                   Officer)                       
  /s/ David L. Shedlarz                                                        
------------------------------   Senior Vice President and        April 23, 1998
      David L. Shedlarz            Chief Financial Officer        
                                   (Principal Financial Officer)  

   /s/ Herbert V. Ryan                                                          
------------------------------   Vice President and Controller    April 23, 1998
       Herbert V. Ryan             (Principal Accounting Officer) 

   /s/ Michael S. Brown                                                        
------------------------------   Director                         April 23, 1998
       Michael S. Brown                                           

   /s/ M. Anthony Burns                                                       
------------------------------   Director                         April 23, 1998
       M. Anthony Burns                                           

    /s/ W. Don Cornwell                                                        
------------------------------   Director                         April 23, 1998
        W. Don Cornwell                                           

   /s/ George B. Harvey                                                       
------------------------------   Director                         April 23, 1998
       George B. Harvey                                           

                                      II-3
Signature                       Title                        Date
          ---------                       -----                        ----

 /s/ Constance J. Horner
-----------------------------   Director                          April 23, 1998
     Constance J. Horner

/s/ Stanley O. Ikenberry
-----------------------------   Director                          April 23, 1998
    Stanley O. Ikenberry

   /s/ Harry P. Kamen
-----------------------------   Director                          April 23, 1998
       Harry P. Kamen

 /s/ Thomas G. Labrecque
-----------------------------   Director                          April 23, 1998
     Thomas G. Labrecque

    /s/ Dana G. Mead
-----------------------------   Director                          April 23, 1998
        Dana G. Mead

 /s/ Henry A. McKinnell
-----------------------------   Director                          April 23, 1998
     Henry A. McKinnell

   /s/ John F. Niblack
-----------------------------   Director                          April 23, 1998
       John F. Niblack

   /s/ Ruth J. Simmons
-----------------------------   Director                          April 23, 1998
       Ruth J. Simmons

  /s/ Jean-Paul Valles
-----------------------------   Director                          April 23, 1998
      Jean-Paul Valles

                                      II-4
EXHIBIT INDEX

EXHIBIT
-------

 5    Opinion and Consent of Margaret M. Foran, Esq., Senior Corporate Counsel 
      and Assistant Secretary

23(b) Consent of KPMG Peat Marwick LLP, independent certified public accountants