As filed with the Securities and Exchange Commission on September 25, 1998

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

                                        Registration No. 333 - _________________

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

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

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

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

                                   SUGEN, Inc.
                             ----------------------
             (Exact name of registrant as specified in its charter)


        DELAWARE                                        13-3629196
------------------------                    ------------------------------------
(State of Incorporation)                    (I.R.S. Employer Identification No.)


                               351 Galveston Drive
                         Redwood City, California 94063
                                 (650) 306-7700
          -------------------------------------------------------------
          (Address and telephone number of principal executive offices)

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

                             1992 STOCK OPTION PLAN
                 1994 NON-EMPLOYEE DIRECTORS' STOCK OPTION PLAN
                 ----------------------------------------------
                            (Full title of the plans)

                               Stephen Evans-Freke
                              Chairman of the Board
                                   SUGEN, Inc.
                               351 Galveston Drive
                         Redwood City, California 94063
                                 (650) 306-7700
--------------------------------------------------------------------------------
 (Name, address, including zip code, and telephone number, including area code,
 of agent for service)
                          -----------------------------
                                   Copies to:
                          Suzanne Sawochka Hooper, Esq.
                               Cooley Godward LLP
                              Five Palo Alto Square
                               Palo Alto, CA 94306
                                 (650) 843-5000
                          -----------------------------
<TABLE>
<CAPTION>
                                               CALCULATION OF REGISTRATION FEE
====================================================================================================================================
       Title of Securities             Amount to be          Proposed Maximum          Proposed Maximum             Amount of
         to be Registered               Registered       Offering Price Per Share  Aggregate Offering Price     Registration Fee
                                                                    (1)                       (1)
------------------------------------------------------------------------------------------------------------------------------------
<S>                                       <C>               <C>        <C>                <C>                       <C>      
Stock Options and Common Stock            900,000           $10.6875 - $17.125            $11,156,942               $3,471.82
(par value $.01)
====================================================================================================================================
<FN>
(1)      Estimated  solely  for the  purpose  of  calculating  the amount of the
         registration   fee  pursuant  to  Rule  457(c)  and  (h)(1)  under  the
         Securities Act of 1933, as amended (the "Securities Act"). The offering
         price per share and  aggregate  offering  price for the unissued  stock
         options and Common Stock are based upon the average of the high and low
         prices of Registrant's  Common Stock as reported on the Nasdaq National
         Market System on September 21, 1998.  The offering  price per share and
         aggregate  offering price for the  outstanding  stock options are based
         upon  the  exercise  prices  of  such  options.   The  following  chart
         illustrates the calculation of the registration fee:
</FN>
</TABLE>
================================================================================
<PAGE>


<TABLE>
<CAPTION>
====================================================================================================================================

                         Title of Shares                             Number of Shares      Offering Price Per    Aggregate Offering
                                                                                                  Share                 Price
------------------------------------------------------------------------------------------------------------------------------------

<S>                                                                       <C>               <C>       <C>            <C>       
Shares issuable pursuant to outstanding stock options pursuant            211,503           $12.625 - $17.125        $2,894,978
to the 1992 Stock Option Plan
------------------------------------------------------------------------------------------------------------------------------------

Shares issuable pursuant to unissued stock options pursuant to            538,497               $12.4375             $6,697,556
the 1992 Stock Option Plan
------------------------------------------------------------------------------------------------------------------------------------

Shares issuable pursuant to unissued stock options pursuant to            150,000               $12.4375             $1,865,625
the 1994 Non-Employee Directors' Stock Option Plan
------------------------------------------------------------------------------------------------------------------------------------

Proposed Maximum Aggregate Offering Price                                                                            $11,458,159
====================================================================================================================================
</TABLE>


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

         Approximate  date of  commencement  of proposed sale to the public:  As
soon as practicable after this Registration Statement becomes effective.


                                        2


<PAGE>

                                EXPLANATORY NOTE

This  Registration  Statement  on Form S-8 is being  filed  for the  purpose  of
registering an additional 750,000 shares of the Registrant's  Common Stock to be
issued  pursuant to the  Registrant's  1992 Stock Option  Plan,  as amended (the
"Option Plan") and an additional 150,000 shares of the Registrant's Common Stock
to be issued pursuant to the  Registrant's  1994  Non-Employee  Directors' Stock
Option Plan, as amended (the "Directors' Plan"). The Registration  Statements on
Form S-8 previously  filed with the  Commission  relating to the Option Plan and
the Directors'  Plan (File No. 33-89270 filed with the Commission on February 8,
1995 and amended on August 1, 1995; File No. 333-09326 filed with the Commission
on August 1, 1996 and File No.  333-30385  filed with the Commission on June 30,
1997) are incorporated by reference herein.


                                    EXHIBITS

Exhibit
Number

5.1           Opinion of Cooley Godward LLP.

23.1          Consent of Ernst & Young LLP, Independent Auditors.

23.2          Consent of Cooley Godward LLP.  Reference is made to Exhibit 5.1.

24.1          Power of Attorney.  Reference is made to the signature pages.

99.1          1992 Stock Option Plan, as amended as of May 20, 1998.

99.2          1994  Non-Employee  Directors' Stock Option Plan, as amended as of
              June 1, 1998.


                                        3


<PAGE>


                                   SIGNATURES

Pursuant to the  requirements  of the  Securities  Act of 1933, as amended,  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  Redwood  City,  County  of San  Mateo,  State  of
California, on September 25, 1998.

                                            SUGEN, Inc.



                                            By        /s/ Stephen Evans-Freke
                                               ---------------------------------
                                                     Stephen Evans-Freke
                                                     Chief Executive Officer and
                                                     Chairman of the Board



                                POWER OF ATTORNEY


KNOW ALL PERSONS BY THESE  PRESENTS,  that each person whose  signature  appears
below constitutes and appoints Stephen Evans-Freke and Susan M. Kanaya, and each
or any one of them, his true and lawful  attorney-in-fact  and agent,  with full
power of substitution  and  resubstitution,  for him and in his name,  place and
stead,  in any and all  capacities,  to sign 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 in connection  therewith,
as fully to all intents and  purposes as he 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 substitutes or substitute,  may lawfully do or cause to be
done by virtue hereof.

<TABLE>
Pursuant to the  requirements of the Securities Act of 1933,  this  Registration
Statement has been signed by the following  persons in the capacities and on the
dates indicated.

<CAPTION>

Signature                                  Title                                          Date


<S>                                        <C>                                            <C>
/s/ Stephen Evans-Freke                    Chief Executive Officer and                    September 25, 1998
----------------------------------         Chairman of the Board   
(Stephen Evans-Freke)                      (Principal Executive and
                                           Financial Officer)      


/s/ Susan M. Kanaya                        Treasurer                                      September 25, 1998
----------------------------------         (Principal Accounting Officer)
(Susan M. Kanaya)


                                        4


<PAGE>





/s/ Axel Ullrich                           Director                                       September 25, 1998
----------------------------------
(Axel Ullrich)



/s/ Richard D. Spizzirri                   Director                                       September 25, 1998
----------------------------------
(Richard D. Spizzirri)



/s/ Jeremy L. Curnock Cook                 Director                                       September 25, 1998
----------------------------------
(Jeremy L. Curnock Cook)



/s/ Heinrich Kuhn                          Director                                       September 25, 1998
----------------------------------
(Heinrich Kuhn)



/s/ Donald E. Nickelson                    Director                                       September 25, 1998
----------------------------------
(Donald E. Nickelson)



/s/ Bruce R. Ross                          Director                                       September 25, 1998
----------------------------------
(Bruce R. Ross)

</TABLE>

                                        5


<PAGE>

<TABLE>
                                                        EXHIBIT INDEX
<CAPTION>

Exhibit                                                                                          Sequential
Number                     Description                                                           Page Number

<S>               <C>                                                                                          <C>
5.1               Opinion of Cooley Godward LLP.                                                                7

23.1              Consent of Ernst & Young LLP, Independent Auditors.                                           8

23.2              Consent of Cooley LLP.  Reference is made to Exhibit 5.1.                                     7

24.1              Power of Attorney.  Reference is made to the signature pages.                                 3

99.1              1992 Stock Option Plan, as amended as of May 20, 1998.                                        9

99.2              1994 Non-Employee Directors' Stock Option Plan, as amended as of June 1, 1998.               19
</TABLE>


                                        6
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 13421}]
{"company-data": {"conformed-name": "SUGEN INC", "cik": "0000908121", "assigned-sic": "2836", "irs-number": "133629196", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-64439", "film-number": "98716380"}, "business-address": {"street1": "351 GALVESTON DR", "city": "REDWOOD CITY", "state": "CA", "zip": "94063-4720", "phone": "6503067700"}, "mail-address": {"street1": "351 GALVESTON DRIVE", "city": "REDWOOD CITY", "state": "CA", "zip": "94063-4720"}}
As filed with the Securities and Exchange Commission on September 25, 1998

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

                                        Registration No. 333 - _________________

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

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

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

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

                                   SUGEN, Inc.
                             ----------------------
             (Exact name of registrant as specified in its charter)

        DELAWARE                                        13-3629196
------------------------                    ------------------------------------
(State of Incorporation)                    (I.R.S. Employer Identification No.)

                               351 Galveston Drive
                         Redwood City, California 94063
                                 (650) 306-7700
          -------------------------------------------------------------
          (Address and telephone number of principal executive offices)

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

                             1992 STOCK OPTION PLAN
                 1994 NON-EMPLOYEE DIRECTORS' STOCK OPTION PLAN
                 ----------------------------------------------
                            (Full title of the plans)

                               Stephen Evans-Freke
                              Chairman of the Board
                                   SUGEN, Inc.
                               351 Galveston Drive
                         Redwood City, California 94063
                                 (650) 306-7700
--------------------------------------------------------------------------------
 (Name, address, including zip code, and telephone number, including area code,
 of agent for service)
                          -----------------------------
                                   Copies to:
                          Suzanne Sawochka Hooper, Esq.
                               Cooley Godward LLP
                              Five Palo Alto Square
                               Palo Alto, CA 94306
                                 (650) 843-5000
                          -----------------------------
CALCULATION OF REGISTRATION FEE
====================================================================================================================================
       Title of Securities             Amount to be          Proposed Maximum          Proposed Maximum             Amount of
         to be Registered               Registered       Offering Price Per Share  Aggregate Offering Price     Registration Fee
                                                                    (1)                       (1)
------------------------------------------------------------------------------------------------------------------------------------
Stock Options and Common Stock            900,000           $10.6875 - $17.125            $11,156,942               $3,471.82
(par value $.01)
====================================================================================================================================
(1)      Estimated  solely  for the  purpose  of  calculating  the amount of the
         registration   fee  pursuant  to  Rule  457(c)  and  (h)(1)  under  the
         Securities Act of 1933, as amended (the "Securities Act"). The offering
         price per share and  aggregate  offering  price for the unissued  stock
         options and Common Stock are based upon the average of the high and low
         prices of Registrant's  Common Stock as reported on the Nasdaq National
         Market System on September 21, 1998.  The offering  price per share and
         aggregate  offering price for the  outstanding  stock options are based
         upon  the  exercise  prices  of  such  options.   The  following  chart
         illustrates the calculation of the registration fee:
================================================================================
====================================================================================================================================

                         Title of Shares                             Number of Shares      Offering Price Per    Aggregate Offering
                                                                                                  Share                 Price
------------------------------------------------------------------------------------------------------------------------------------
Shares issuable pursuant to outstanding stock options pursuant            211,503           $12.625 - $17.125        $2,894,978
to the 1992 Stock Option Plan
------------------------------------------------------------------------------------------------------------------------------------

Shares issuable pursuant to unissued stock options pursuant to            538,497               $12.4375             $6,697,556
the 1992 Stock Option Plan
------------------------------------------------------------------------------------------------------------------------------------

Shares issuable pursuant to unissued stock options pursuant to            150,000               $12.4375             $1,865,625
the 1994 Non-Employee Directors' Stock Option Plan
------------------------------------------------------------------------------------------------------------------------------------

Proposed Maximum Aggregate Offering Price                                                                            $11,458,159
====================================================================================================================================
--------------------------------------------------------------------------------

         Approximate  date of  commencement  of proposed sale to the public:  As
soon as practicable after this Registration Statement becomes effective.

                                        2
EXPLANATORY NOTE

This  Registration  Statement  on Form S-8 is being  filed  for the  purpose  of
registering an additional 750,000 shares of the Registrant's  Common Stock to be
issued  pursuant to the  Registrant's  1992 Stock Option  Plan,  as amended (the
"Option Plan") and an additional 150,000 shares of the Registrant's Common Stock
to be issued pursuant to the  Registrant's  1994  Non-Employee  Directors' Stock
Option Plan, as amended (the "Directors' Plan"). The Registration  Statements on
Form S-8 previously  filed with the  Commission  relating to the Option Plan and
the Directors'  Plan (File No. 33-89270 filed with the Commission on February 8,
1995 and amended on August 1, 1995; File No. 333-09326 filed with the Commission
on August 1, 1996 and File No.  333-30385  filed with the Commission on June 30,
1997) are incorporated by reference herein.

                                    EXHIBITS

Exhibit
Number

5.1           Opinion of Cooley Godward LLP.

23.1          Consent of Ernst & Young LLP, Independent Auditors.

23.2          Consent of Cooley Godward LLP.  Reference is made to Exhibit 5.1.

24.1          Power of Attorney.  Reference is made to the signature pages.

99.1          1992 Stock Option Plan, as amended as of May 20, 1998.

99.2          1994  Non-Employee  Directors' Stock Option Plan, as amended as of
              June 1, 1998.

                                        3
SIGNATURES

Pursuant to the  requirements  of the  Securities  Act of 1933, as amended,  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  Redwood  City,  County  of San  Mateo,  State  of
California, on September 25, 1998.

                                            SUGEN, Inc.

                                            By        /s/ Stephen Evans-Freke
                                               ---------------------------------
                                                     Stephen Evans-Freke
                                                     Chief Executive Officer and
                                                     Chairman of the Board

                                POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE  PRESENTS,  that each person whose  signature  appears
below constitutes and appoints Stephen Evans-Freke and Susan M. Kanaya, and each
or any one of them, his true and lawful  attorney-in-fact  and agent,  with full
power of substitution  and  resubstitution,  for him and in his name,  place and
stead,  in any and all  capacities,  to sign 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 in connection  therewith,
as fully to all intents and  purposes as he 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 substitutes or substitute,  may lawfully do or cause to be
done by virtue hereof.

Pursuant to the  requirements of the Securities Act of 1933,  this  Registration
Statement has been signed by the following  persons in the capacities and on the
dates indicated.
Signature                                  Title                                          Date
/s/ Stephen Evans-Freke                    Chief Executive Officer and                    September 25, 1998
----------------------------------         Chairman of the Board   
(Stephen Evans-Freke)                      (Principal Executive and
                                           Financial Officer)      

/s/ Susan M. Kanaya                        Treasurer                                      September 25, 1998
----------------------------------         (Principal Accounting Officer)
(Susan M. Kanaya)

                                        4
/s/ Axel Ullrich                           Director                                       September 25, 1998
----------------------------------
(Axel Ullrich)

/s/ Richard D. Spizzirri                   Director                                       September 25, 1998
----------------------------------
(Richard D. Spizzirri)

/s/ Jeremy L. Curnock Cook                 Director                                       September 25, 1998
----------------------------------
(Jeremy L. Curnock Cook)

/s/ Heinrich Kuhn                          Director                                       September 25, 1998
----------------------------------
(Heinrich Kuhn)

/s/ Donald E. Nickelson                    Director                                       September 25, 1998
----------------------------------
(Donald E. Nickelson)

/s/ Bruce R. Ross                          Director                                       September 25, 1998
----------------------------------
(Bruce R. Ross)
5
EXHIBIT INDEX
Exhibit                                                                                          Sequential
Number                     Description                                                           Page Number
5.1               Opinion of Cooley Godward LLP.                                                                7

23.1              Consent of Ernst & Young LLP, Independent Auditors.                                           8

23.2              Consent of Cooley LLP.  Reference is made to Exhibit 5.1.                                     7

24.1              Power of Attorney.  Reference is made to the signature pages.                                 3

99.1              1992 Stock Option Plan, as amended as of May 20, 1998.                                        9

99.2              1994 Non-Employee Directors' Stock Option Plan, as amended as of June 1, 1998.               19
6