<PAGE>   1
    As filed with the Securities and Exchange Commission on January 26, 1999
                                                     Registration No. 333-______
================================================================================


                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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

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

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

                                GERON CORPORATION
             (Exact name of Registrant as specified in its charter)

           Delaware                                  75-2287752
   (State of Incorporation)             (I.R.S. Employer Identification No.)

                             230 CONSTITUTION DRIVE
                              MENLO PARK, CA 94025
                    (Address of principal executive offices)

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

                             1992 STOCK OPTION PLAN
                            (Full title of the Plan)

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

                                RONALD W. EASTMAN
                      PRESIDENT AND CHIEF EXECUTIVE OFFICER
                                GERON CORPORATION
                             230 CONSTITUTION DRIVE
                              MENLO PARK, CA 94025
                                 (650) 473-7700
(Name, address and telephone number, including area code, of agent for service)

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

                                    COPY TO:

                                   SCOTT RING
                                VENTURE LAW GROUP
                               2800 SAND HILL ROAD
                          MENLO PARK, CALIFORNIA 94025
                                 (650) 233-8454


               (Calculation of Registration Fee on following page)

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


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


<PAGE>   2


                        CALCULATION OF REGISTRATION FEE


<TABLE>
<CAPTION>
===============================================================================================
                                                    PROPOSED          PROPOSED
                                    AMOUNT TO       MAXIMUM           MAXIMUM        AMOUNT OF
    TITLE OF SECURITIES TO BE          BE        OFFERING PRICE      AGGREGATE     REGISTRATION
           REGISTERED              REGISTERED(1)   PER SHARE       OFFERING PRICE       FEE
-----------------------------------------------------------------------------------------------
1992 STOCK OPTION PLAN
-----------------------------------------------------------------------------------------------
<S>                               <C>               <C>               <C>              <C>   
  Common Stock, $0.001
    par value.................    500,000 shares    $12.00(2)         $6,000,000       $1,668
===============================================================================================
</TABLE>

(1)  This Registration Statement shall also cover any additional shares of
     Common Stock which become issuable under the 1992 Stock Option Plan by
     reason of any stock dividend, stock split, recapitalization or any other
     similar transaction effected without the receipt of consideration which
     results in an increase in the number of the Registrant's outstanding shares
     of Common Stock.

(2)  Estimated in accordance with Rule 457(h) under the Securities Act solely
     for the purpose of calculating the registration fee. The computation is
     based upon the average of the high and low prices of Geron Corporation's
     Common Stock as reported on The Nasdaq National Market on January 25, 1999.


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


                                      -2-
<PAGE>   3

                                     PART II
               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT


Item 3.        INCORPORATION OF DOCUMENTS BY REFERENCE.

        The following documents filed with the Securities and Exchange
Commission (the "Commission") are hereby incorporated by reference:

        (a) The Registrant's Annual Report on Form 10-K for the fiscal year
ended December 31, 1997 pursuant to Section 13(a) of the Securities Exchange Act
of 1934, as amended (the "Exchange Act"), which contains audited financial
statements for the Registrant's latest fiscal year for which such statements
have been filed (File No. 0-20859).

        (b) All other reports filed by the Registrant pursuant to Sections 13(a)
or 15(d) of the Exchange Act since the end of the fiscal year covered by the
audited financial statements in (a) above.

        (c) The description of the Registrant's Common Stock contained in the
Registrant's Registration Statement on Form 8-A filed with the Commission under
Section 12 of the Exchange Act on June 13, 1996. (File No. 0-20859).

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

Item 4.        DESCRIPTION OF SECURITIES.  Not applicable.

Item 5.        INTERESTS OF NAMED EXPERTS AND COUNSEL.  Not applicable.

Item 6.        INDEMNIFICATION OF DIRECTORS AND OFFICERS.

        Section 145 of the Delaware General Corporation Law authorizes a court
to award or a corporation's Board of Directors to grant indemnification to
directors and officers in terms sufficiently broad to permit such
indemnification under certain circumstances for liabilities (including
reimbursement for expenses incurred) arising under the 1933 Act. Article VII,
Section 6 of the Registrant's Bylaws provides for mandatory indemnification of
its directors and officers and permissible indemnification of employees and
other agents to the maximum extent permitted by the Delaware General Corporation
Law. The Registrant's Certificate of Incorporation provides that, pursuant to
Delaware law, its directors shall not be liable for monetary damages for breach
of the directors' fiduciary duty as directors to the Registrant and its
stockholders. This provision in the Certificate of Incorporation does not
eliminate the directors' fiduciary duty, and in appropriate circumstances
equitable remedies such as injunctive or other forms of non-monetary relief will
remain available under Delaware law. In addition, each director will continue to
be subject to liability for breach of the director's duty of loyalty to the
Registrant for acts or omissions not in good faith or involving intentional
misconduct, for knowing violations of law, for actions leading to improper
personal benefit to the director, and for payment of dividends or approval of
stock repurchases or redemptions that are unlawful under Delaware law. The
provision also does not affect a director's responsibilities under any other
law, such as the federal securities laws or state or federal environmental laws.
The Registrant has entered into Indemnification Agreements with its officers and
directors which provide such officers and directors with further indemnification
to the maximum extent permitted by the Delaware General Corporation Law.

Item 7.        EXEMPTION FROM REGISTRATION CLAIMED.  Not applicable.



                                      -3-
<PAGE>   4

Item 8.        EXHIBITS.

<TABLE>
<CAPTION>
                  Exhibit
                  Number
                  -------

                  <S>       <C>
                  5.1       Opinion of Venture Law Group, A Professional
                            Corporation

                  23.1      Consent of Venture Law Group, A Professional
                            Corporation (included in Exhibit 5.1)

                  23.2      Consent of Ernst & Young LLP, Independent Auditors

                  24.1      Power of Attorney (see page 6)

                  99.1      1992 Stock Option Plan, as amended
</TABLE>

Item 9.        UNDERTAKINGS.

        A.     The undersigned Registrant hereby undertakes:

               (1) to file, during any period in which offers or sales are being
made, a post-effective amendment to this registration statement 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.

               (2) that, for purposes of determining any liability under the
Securities Act, each such post-effective amendment shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

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

        B.     The undersigned Registrant hereby undertakes that, for purposes
of determining any liability under the Securities Act, each filing of the
Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Exchange Act that is incorporated by reference in the registration statement
shall be deemed to be a new registration statement relating to the securities
offered therein, and the offering of such securities at that time shall be
deemed to be the initial bona fide offering thereof.

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



                            [Signature Pages Follow]



                                      -4-
<PAGE>   5

                                   SIGNATURES


        Pursuant to the requirements of the Securities Act of 1933, the
Registrant, Geron Corporation, a corporation organized and existing under the
laws of the State of Delaware, 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 Menlo Park, State of
California, on this 26th day of January 1999.



                                     Geron Corporation



                                     By:  /s/ David L. Greenwood
                                         --------------------------------------
                                          David L. Greenwood
                                          Chief Financial Officer













<PAGE>   6

                                POWER OF ATTORNEY

        KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Ronald W. Eastman and David L. Greenwood,
jointly and severally, his attorneys-in-fact and agents, each with the power of
substitution and resubstitution, for him and in his name, place or stead, in any
and all capacities, to sign any amendments to this Registration Statement on
Form S-8, and to file such amendments, together with exhibits and other
documents in connection therewith, with the Securities and Exchange Commission,
granting to each attorney-in-fact and agent, full power and authority to do and
perform each and every act and thing requisite and necessary to be done in and
about the premises, as fully as he might or could do in person, and ratifying
and confirming all that the attorneys-in-fact and agents, or his or her
substitute or substitutes, may 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.


<TABLE>
<CAPTION>
           Signature                             Title                         Date
           ---------                             -----                         ----
<S>                               <C>                                      <C> 
/s/ Ronald W. Eastman             President, Chief Executive Officer       January 26, 1999
-----------------------------       (Principal Executive Officer)
Ronald W. Eastman


/s/ David L. Greenwood            Chief Financial Officer, Vice            January 26, 1999
-----------------------------       President of Corporate                                                       
David L. Greenwood                  Development, Treasurer,
                                    Secretary (Principal Financial
                                    and Accounting Officer)


/s/ Alexander E. Barkas           Director                                 January 26, 1999
-----------------------------
Alexander E. Barkas, Ph.D.


/s/ Edward V. Fritzky             Director                                 January 26, 1999
-----------------------------
Edward V. Fritzky


-----------------------------     Director                                 January __, 1999
Thomas D. Kiley


/s/ Gary L. Neil                  Director                                 January 26, 1999
-----------------------------                                                              
Gary L. Neil


/s/ Robert B. Stein               Director                                 January 26, 1999
-----------------------------                                                              
Robert B. Stein, M.D., Ph.D.


/s/ John P. Walker                Director                                 January 26, 1999
-----------------------------                                                              
John P. Walker
</TABLE>




<PAGE>   7



                                INDEX TO EXHIBITS



<TABLE>
<CAPTION>
Exhibit Number
-------------- 
<S>             <C>
     5.1        Opinion of Venture Law Group, A Professional Corporation 

    23.1        Consent of Venture Law Group, A Professional Corporation 
                (included in Exhibit 5.1)

    23.2        Consent of Ernst & Young LLP, Independent Auditors

    24.1        Power of Attorney (see page 6)

    99.1        1992 Stock Option Plan, as amended
</TABLE>
[{"type": "S-8", "sequence": "1", "description": "STOCK OPTION PLAN", "secsgml_size_bytes": 15736}]
{"company-data": {"conformed-name": "GERON CORPORATION", "cik": "0000886744", "assigned-sic": "2834", "irs-number": "752287752", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-71181", "film-number": "99513092"}, "business-address": {"street1": "230 CONSTITUTION DRIVE", "city": "MENLO PARK", "state": "CA", "zip": "94025", "phone": "4154737700"}, "mail-address": {"street1": "200 CONSTITUTION DRIVE", "city": "MENLO PARK", "state": "CA", "zip": "94025"}}
1
    As filed with the Securities and Exchange Commission on January 26, 1999
                                                     Registration No. 333-______
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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

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

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

                                GERON CORPORATION
             (Exact name of Registrant as specified in its charter)

           Delaware                                  75-2287752
   (State of Incorporation)             (I.R.S. Employer Identification No.)

                             230 CONSTITUTION DRIVE
                              MENLO PARK, CA 94025
                    (Address of principal executive offices)

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

                             1992 STOCK OPTION PLAN
                            (Full title of the Plan)

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

                                RONALD W. EASTMAN
                      PRESIDENT AND CHIEF EXECUTIVE OFFICER
                                GERON CORPORATION
                             230 CONSTITUTION DRIVE
                              MENLO PARK, CA 94025
                                 (650) 473-7700
(Name, address and telephone number, including area code, of agent for service)

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

                                    COPY TO:

                                   SCOTT RING
                                VENTURE LAW GROUP
                               2800 SAND HILL ROAD
                          MENLO PARK, CALIFORNIA 94025
                                 (650) 233-8454

               (Calculation of Registration Fee on following page)

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

================================================================================
2

                        CALCULATION OF REGISTRATION FEE
===============================================================================================
                                                    PROPOSED          PROPOSED
                                    AMOUNT TO       MAXIMUM           MAXIMUM        AMOUNT OF
    TITLE OF SECURITIES TO BE          BE        OFFERING PRICE      AGGREGATE     REGISTRATION
           REGISTERED              REGISTERED(1)   PER SHARE       OFFERING PRICE       FEE
-----------------------------------------------------------------------------------------------
1992 STOCK OPTION PLAN
-----------------------------------------------------------------------------------------------
Common Stock, $0.001
    par value.................    500,000 shares    $12.00(2)         $6,000,000       $1,668
===============================================================================================
(1)  This Registration Statement shall also cover any additional shares of
     Common Stock which become issuable under the 1992 Stock Option Plan by
     reason of any stock dividend, stock split, recapitalization or any other
     similar transaction effected without the receipt of consideration which
     results in an increase in the number of the Registrant's outstanding shares
     of Common Stock.

(2)  Estimated in accordance with Rule 457(h) under the Securities Act solely
     for the purpose of calculating the registration fee. The computation is
     based upon the average of the high and low prices of Geron Corporation's
     Common Stock as reported on The Nasdaq National Market on January 25, 1999.

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

                                      -2-
3

                                     PART II
               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.        INCORPORATION OF DOCUMENTS BY REFERENCE.

        The following documents filed with the Securities and Exchange
Commission (the "Commission") are hereby incorporated by reference:

        (a) The Registrant's Annual Report on Form 10-K for the fiscal year
ended December 31, 1997 pursuant to Section 13(a) of the Securities Exchange Act
of 1934, as amended (the "Exchange Act"), which contains audited financial
statements for the Registrant's latest fiscal year for which such statements
have been filed (File No. 0-20859).

        (b) All other reports filed by the Registrant pursuant to Sections 13(a)
or 15(d) of the Exchange Act since the end of the fiscal year covered by the
audited financial statements in (a) above.

        (c) The description of the Registrant's Common Stock contained in the
Registrant's Registration Statement on Form 8-A filed with the Commission under
Section 12 of the Exchange Act on June 13, 1996. (File No. 0-20859).

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

Item 4.        DESCRIPTION OF SECURITIES.  Not applicable.

Item 5.        INTERESTS OF NAMED EXPERTS AND COUNSEL.  Not applicable.

Item 6.        INDEMNIFICATION OF DIRECTORS AND OFFICERS.

        Section 145 of the Delaware General Corporation Law authorizes a court
to award or a corporation's Board of Directors to grant indemnification to
directors and officers in terms sufficiently broad to permit such
indemnification under certain circumstances for liabilities (including
reimbursement for expenses incurred) arising under the 1933 Act. Article VII,
Section 6 of the Registrant's Bylaws provides for mandatory indemnification of
its directors and officers and permissible indemnification of employees and
other agents to the maximum extent permitted by the Delaware General Corporation
Law. The Registrant's Certificate of Incorporation provides that, pursuant to
Delaware law, its directors shall not be liable for monetary damages for breach
of the directors' fiduciary duty as directors to the Registrant and its
stockholders. This provision in the Certificate of Incorporation does not
eliminate the directors' fiduciary duty, and in appropriate circumstances
equitable remedies such as injunctive or other forms of non-monetary relief will
remain available under Delaware law. In addition, each director will continue to
be subject to liability for breach of the director's duty of loyalty to the
Registrant for acts or omissions not in good faith or involving intentional
misconduct, for knowing violations of law, for actions leading to improper
personal benefit to the director, and for payment of dividends or approval of
stock repurchases or redemptions that are unlawful under Delaware law. The
provision also does not affect a director's responsibilities under any other
law, such as the federal securities laws or state or federal environmental laws.
The Registrant has entered into Indemnification Agreements with its officers and
directors which provide such officers and directors with further indemnification
to the maximum extent permitted by the Delaware General Corporation Law.

Item 7.        EXEMPTION FROM REGISTRATION CLAIMED.  Not applicable.

                                      -3-
4

Item 8.        EXHIBITS.
Exhibit
                  Number
                  -------
5.1       Opinion of Venture Law Group, A Professional
                            Corporation

                  23.1      Consent of Venture Law Group, A Professional
                            Corporation (included in Exhibit 5.1)

                  23.2      Consent of Ernst & Young LLP, Independent Auditors

                  24.1      Power of Attorney (see page 6)

                  99.1      1992 Stock Option Plan, as amended
Item 9.        UNDERTAKINGS.

        A.     The undersigned Registrant hereby undertakes:

               (1) to file, during any period in which offers or sales are being
made, a post-effective amendment to this registration statement 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.

               (2) that, for purposes of determining any liability under the
Securities Act, each such post-effective amendment shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

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

        B.     The undersigned Registrant hereby undertakes that, for purposes
of determining any liability under the Securities Act, each filing of the
Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Exchange Act that is incorporated by reference in the registration statement
shall be deemed to be a new registration statement relating to the securities
offered therein, and the offering of such securities at that time shall be
deemed to be the initial bona fide offering thereof.

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

                            [Signature Pages Follow]

                                      -4-
5

                                   SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, the
Registrant, Geron Corporation, a corporation organized and existing under the
laws of the State of Delaware, 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 Menlo Park, State of
California, on this 26th day of January 1999.

                                     Geron Corporation

                                     By:  /s/ David L. Greenwood
                                         --------------------------------------
                                          David L. Greenwood
                                          Chief Financial Officer
6

                                POWER OF ATTORNEY

        KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Ronald W. Eastman and David L. Greenwood,
jointly and severally, his attorneys-in-fact and agents, each with the power of
substitution and resubstitution, for him and in his name, place or stead, in any
and all capacities, to sign any amendments to this Registration Statement on
Form S-8, and to file such amendments, together with exhibits and other
documents in connection therewith, with the Securities and Exchange Commission,
granting to each attorney-in-fact and agent, full power and authority to do and
perform each and every act and thing requisite and necessary to be done in and
about the premises, as fully as he might or could do in person, and ratifying
and confirming all that the attorneys-in-fact and agents, or his or her
substitute or substitutes, may 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/ Ronald W. Eastman             President, Chief Executive Officer       January 26, 1999
-----------------------------       (Principal Executive Officer)
Ronald W. Eastman

/s/ David L. Greenwood            Chief Financial Officer, Vice            January 26, 1999
-----------------------------       President of Corporate                                                       
David L. Greenwood                  Development, Treasurer,
                                    Secretary (Principal Financial
                                    and Accounting Officer)

/s/ Alexander E. Barkas           Director                                 January 26, 1999
-----------------------------
Alexander E. Barkas, Ph.D.

/s/ Edward V. Fritzky             Director                                 January 26, 1999
-----------------------------
Edward V. Fritzky

-----------------------------     Director                                 January __, 1999
Thomas D. Kiley

/s/ Gary L. Neil                  Director                                 January 26, 1999
-----------------------------                                                              
Gary L. Neil

/s/ Robert B. Stein               Director                                 January 26, 1999
-----------------------------                                                              
Robert B. Stein, M.D., Ph.D.

/s/ John P. Walker                Director                                 January 26, 1999
-----------------------------                                                              
John P. Walker
7

                                INDEX TO EXHIBITS
Exhibit Number
--------------
5.1        Opinion of Venture Law Group, A Professional Corporation 

    23.1        Consent of Venture Law Group, A Professional Corporation 
                (included in Exhibit 5.1)

    23.2        Consent of Ernst & Young LLP, Independent Auditors

    24.1        Power of Attorney (see page 6)

    99.1        1992 Stock Option Plan, as amended