<PAGE>
 
     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON MAY 22, 1998
                                                      Registration No. 333-
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

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

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

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

                              SIEBEL SYSTEMS, INC.
             (Exact name of registrant as specified in its charter)

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


      DELAWARE                                           94-3187233
(State of Incorporation)                    (I.R.S. Employer Identification No.)

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

                            1855 SOUTH GRANT STREET
                          SAN MATEO, CALIFORNIA 94402
                    (Address of principal executive offices)
                         -----------------------------

                            SCOPUS TECHNOLOGY, INC.
                           1995 DIRECTOR OPTION PLAN

                            SCOPUS TECHNOLOGY, INC.
                             1991 STOCK OPTION PLAN
                            (Full Title of the Plan)
                                        
                                THOMAS M. SIEBEL
                      CHAIRMAN AND CHIEF EXECUTIVE OFFICER
                              SIEBEL SYSTEMS, INC.
                            1855 SOUTH GRANT STREET
                          SAN MATEO, CALIFORNIA 94402
                                 (650) 295-5000
 (Name, address, including zip code, and telephone number, including area code,
                             of agent for service)
                          ----------------------------

                                   Copies to:
                              ERIC C. JENSEN, ESQ.
                               COOLEY GODWARD LLP
                              3000 SAND HILL ROAD
                             BUILDING 3, SUITE 230
                       MENLO PARK, CALIFORNIA 94025-7116
                                 (650) 843-5000
                          ----------------------------
                                        
     This Registration Statement will become effective immediately upon filing
 with the Securities and Exchange Commission.  Sales of the registered
 securities will begin as soon as reasonably practicable after the effective
 date of this Registration Statement.

                        CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>
==================================================================================================================================
                                                               PROPOSED MAXIMUM           PROPOSED MAXIMUM    
TITLE OF SECURITIES TO BE           AMOUNT TO BE              OFFERING PRICE PER          AGGREGATE OFFERING        AMOUNT OF 
     REGISTERED                     REGISTERED (1)                 SHARE (2)                  PRICE (1)          REGISTRATION FEE
----------------------------------------------------------------------------------------------------------------------------------
<S>                               <C>                     <C>                        <C>                        <C>
Common Stock (par value $.001)                                                                                         $1911

1991 Scopus Stock Option Plan         3,513,000                     $ 1.39                 $4,883,070 

1995 Scopus Director Plan                62,000                     $25.67                 $1,591,540  
</TABLE>

(1)  This Registration Statement shall cover any additional shares of Common
     Stock which become issuable under the plans set forth herein by reason of
     any stock dividend, stock split, recapitalization or any other similar
     transaction without receipt of consideration which results in an increase
     in the number of shares of the Company's outstanding Common Stock.
<PAGE>
 
(2)  Calculated solely for the purposes of this offering under Rule 457(h)
     promulgated under the Securities Act of 1933, as amended (the "Securities
     Act"), on the basis of the price at which the options may be exercised.
     The price per share and aggregate offering price is based upon the weighted
     average exercise price pursuant to Rule 457(h) of the Securities Act, of
     the options assumed as follows:

     Options to purchase 62,000 shares of Siebel Systems, Inc. Common Stock
     issued pursuant to the 1995 Director Option Plan at an average exercise
     price of $25.67 per share.

     Options to purchase 3,513,000 shares of Siebel Systems, Inc. Common Stock
     issued pursuant to the 1991 Stock Option Plan at an average exercise price
     of $1.39 per share.

                                       2.
<PAGE>
 
The shares registered hereunder will be issued upon the exercise of stock
options assumed by Siebel Systems, Inc., a Delaware corporation (the
"Registrant"), pursuant to that certain Agreement and Plan of Merger and
Reorganization among the Registrant, Syracuse Acquisition Sub, Inc. and Scopus
Technology, Inc ("Scopus"), dated March 1, 1998.  These options were originally
granted to directors of Scopus under Scopus' 1995 Director Option Plan and to
employees and consultants under Scopus' 1991 Stock Option Plan.

                                       3.
<PAGE>
 
                                    PART II

ITEM 3.  INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE.

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

     (a) The Registrant's Annual Report on Form 10-K for the year ended December
31, 1997 (File No. 0-20725), including all material incorporated by reference
therein;

     (b) The Registrant's Quarterly Report on Form 10-Q for the quarter ended
March 31, 1998 (File No. 0-20725), including all material incorporated by
reference therein;

     (c) The Registrant's Current Report on Form 8-K (File No. 0-20725), dated
March 31, 1998;

     (d) The Registrant's Current Report on Form 8-K (File No. 0-20725), dated
May 19, 1998; and

     (e) The description of the Common Stock contained in the Registrant's
Registration Statement on Form 8-A (File No. 0-20725).

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

ITEM 4.  DESCRIPTION OF SECURITIES.

         Not applicable.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.

     The validity of the issuance of the Common Stock offered hereby will be
passed upon for the Company by Cooley Godward LLP ("Cooley Godward").  As of the
date of the Prospectus, certain members and associates of Cooley Godward own an
aggregate of 28,446 shares of Common Stock. In addition, James C. Gaither, a
director and the Secretary of the Company and a partner of Cooley Godward, owns
119,314 shares of Common Stock and has options to purchase 44,000 shares of
Common Stock.  Eric C. Jensen, a partner of Cooley Godward, is an Assistant
Secretary of the Company.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.

     Under Section 145 of the Delaware General Corporation Law, the Registrant
has broad powers to indemnify its directors and officers against liabilities
they may incur in such capacities, including liabilities under the Securities
Act.

     The Registrant's Certificate of Incorporation, as amended, provides for the
elimination of liability for monetary damages for breach of the directors'
fiduciary duty of care to the Registrant and its stockholders.  These provisions
do not eliminate the directors' duty of care and, in appropriate circumstances,
equitable remedies such an 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 any transaction from which the
director derived an improper personal benefit, and for payment of dividends or
approval of stock repurchases or redemptions that are unlawful under Delaware
law.  The provision does not affect a 
<PAGE>
 
director's responsibilities under any other laws, such as the federal securities
laws or state or federal environmental laws.

     The Registrant has entered into agreements with its directors and executive
officers that require the Registrant to indemnify such persons against expenses,
judgments, fines, settlements and other amounts actually and reasonably incurred
(including expenses of a derivative action) in connection with any proceeding,
whether actual or threatened, to which any such person may be made a party by
reason of the fact that such person is or was a director or officer of the
Registrant or any of its affiliated enterprises, provided such person acted in
good faith and in a manner such person reasonably believed to be in or not
opposed to the best interests of the Registrant and, with respect to any
criminal proceeding, had no reasonable cause to believe his or her conduct was
unlawful.  The indemnification agreements also set forth certain procedures that
will apply in the event of a claim for indemnification thereunder.



ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.
         Not applicable.

ITEM 8.  EXHIBITS.

EXHIBIT
NUMBER  DESCRIPTION

 4.1    Restated Certificate of Incorporation of the Registrant, as amended to
        date./1/

 4.2    Bylaws of the Registrant./2/
 
 4.3    Specimen Stock Certificate./2/

 4.4    Restated Investor Rights Agreement, dated December 1, 1995, between the
        Registrant and certain investors, as amended April 30, 1996 and June 14,
        1996./2/

 5.1    Opinion of Cooley Godward LLP./3/

23.1    Consent of KPMG Peat Marwick LLP, Independent Auditors. /3/

23.2    Consent of Cooley Godward LLP is contained in Exhibit 5.1 to this
        Registration Statement.

24.1    Power of Attorney is contained on the signature pages. /3/

99.1    Scopus Technology, Inc. 1995 Director Option Plan. /3/

99.2    Form of option agreement under the Scopus Technology, Inc. 1995 Director
        Option Plan. /3/

99.3    Scopus Technology, Inc. 1991 Stock Option Plan. /3/

99.4    Form of option agreement under the Scopus Technology, Inc. 1991 Stock
        Option Plan. /3/
--------------------------------------------------------------------------------
/1/     Incorporated by reference to the Registrant's Registration Statement on
                Form S-8 (No. 333 07983), as amended.

/2/     Incorporated by reference to the Registrant's Registration Statement on
                Form S-1 (No. 333-03751), as amended.

/3/     Filed herewith.
<PAGE>
 
ITEM 9.  UNDERTAKINGS.

   A.  The undersigned registrant hereby undertakes:

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

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

       (ii) To reflect in the prospectus any facts or events arising after the
       effective date of the Registration Statement (or the most recent post-
       effective amendment thereof) which, individually or in the aggregate,
       represent a fundamental change in the information set forth in the
       Registration Statement.  Notwithstanding the foregoing, any increase or
       decrease in volume of securities offered (if the total dollar value of
       securities offered would not exceed that which was registered) and any
       deviation from the low or high and of the estimated maximum offering
       range may be reflected in the form of prospectus filed with the
       Commission pursuant to Rule 424(b) if, in the aggregate, the changes in
       volume and price represent no more than twenty percent (20%) change in
       the maximum aggregate offering price set forth in the "Calculation of
       Registration Fee" table in the effective Registration Statement.

       (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 paragraphs (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 paragraphs is contained in periodic reports filed with or
furnished to the Commission by the Registrant pursuant to Section 13 or 15(d) of
the Exchange Act that are incorporated by reference in the Registration
Statement.

     (2) That, for the purpose of determining any liability under the Securities
Act, each such post-effective amendment shall be deemed to be a new Registration
Statement relating to the securities offered herein, 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 (and, where applicable, each filing of an employee benefit plan's
annual report pursuant to section 15(d) of the Exchange Act) that is
incorporated by reference in the 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.

   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 Securities and Exchange Commission
such indemnification is against public policy as expressed in the Securities Act
and is, therefore, unenforceable.  In the event that a claim for indemnification
against such liabilities (other than the payment by the Registrant of expenses
incurred or paid by a director, officer or controlling person of the Registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question 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.
<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 San Mateo, State of California, on this 21st day of
May, 1998.


                                 SIEBEL SYSTEMS, INC.



                                 By:  /s/ Thomas M. Siebel
                                    ---------------------------------
                                    Thomas M. Siebel
                                    Chairman of the Board of Directors and Chief
                                    Executive Officer
<PAGE>
 
                               POWER OF ATTORNEY

   KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears
below constitutes and appoints Thomas M. Siebel and Howard H. Graham, 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.

<TABLE>
<CAPTION>
               SIGNATURE                                       TITLE                                   DATE
               ---------                                       -----                                   ----
<S>                                                <C>                                       <C>
          /s/ Thomas M. Siebel                     Chairman of the Board of                        May 21, 1998
----------------------------------------           Directors and Chief Executive
        Thomas M. Siebel                           Officer
                                                   (Principal Executive Officer)

          /s/ Howard H. Graham                     Senior Vice President Finance                   May 21, 1998
----------------------------------------           and Administration and Chief
        Howard H. Graham                           Financial Officer
                                                   (Principal Financial and
                                                   Accounting Officer)

          /s/ Eric E. Schmidt                      Director                                        May 21, 1998
----------------------------------------
        Eric E. Schmidt

          /s/ James C. Gaither                     Director                                        May 21, 1998
----------------------------------------
        James C. Gaither

          /s/ George T. Shaheen                    Director                                        May 21, 1998
----------------------------------------
        George T. Shaheen

          /s/ Charles R. Schwab                    Director                                        May 21, 1998
----------------------------------------
        Charles R. Schwab

          /s/ A. Michael Spence                    Director                                        May 21, 1998
----------------------------------------
        A. Michael Spence
</TABLE>
<PAGE>
 
                                 EXHIBIT INDEX

EXHIBIT
NUMBER  DESCRIPTION

 4.1    Restated Certificate of Incorporation of the Registrant, as amended to
        date./1/

 4.2    Bylaws of the Registrant./2/
 
 4.3    Specimen Stock Certificate./2/

 4.4    Restated Investor Rights Agreement, dated December 1, 1995, between the
        Registrant and certain investors, as amended April 30, 1996 and June 14,
        1996./2/

 5.1    Opinion of Cooley Godward LLP./3/

23.1    Consent of KPMG Peat Marwick LLP, Independent Auditors. /3/

23.2    Consent of Cooley Godward LLP is contained in Exhibit 5.1 to this
        Registration Statement.

24.1    Power of Attorney is contained on the signature pages. /3/

99.1    Scopus Technology, Inc. 1995 Director Option Plan. /3/

99.2    Form of option agreement under the Scopus Technology, Inc. 1995 Director
        Option Plan. /3/

99.3    Scopus Technology, Inc. 1991 Stock Option Plan. /3/

99.4    Form of option agreement under the Scopus Technology, Inc. 1991 Stock
        Option Plan. /3/
--------------------------------------------------------------------------------
/1/     Incorporated by reference to the Registrant's Registration Statement on
                Form S-8 (No. 333 07983), as amended.

/2/     Incorporated by reference to the Registrant's Registration Statement on
                Form S-1 (No. 333-03751), as amended.

/3/     Filed herewith.
[{"type": "S-8", "sequence": "1", "description": "REGISTRATION STATEMENT", "secsgml_size_bytes": 21454}]
{"company-data": {"conformed-name": "SIEBEL SYSTEMS INC", "cik": "0001006835", "assigned-sic": "7372", "irs-number": "943187233", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-53369", "film-number": "98630233"}, "business-address": {"street1": "1885 SOUTH GRANT STREET", "city": "SAN MATEO", "state": "CA", "zip": "94402", "phone": "4152955000"}, "mail-address": {"street1": "1885 SOUTH GRANT STREET", "city": "SAN MATEO", "state": "CA", "zip": "94402"}}
AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON MAY 22, 1998
                                                      Registration No. 333-
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

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

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

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

                              SIEBEL SYSTEMS, INC.
             (Exact name of registrant as specified in its charter)

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

      DELAWARE                                           94-3187233
(State of Incorporation)                    (I.R.S. Employer Identification No.)

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

                            1855 SOUTH GRANT STREET
                          SAN MATEO, CALIFORNIA 94402
                    (Address of principal executive offices)
                         -----------------------------

                            SCOPUS TECHNOLOGY, INC.
                           1995 DIRECTOR OPTION PLAN

                            SCOPUS TECHNOLOGY, INC.
                             1991 STOCK OPTION PLAN
                            (Full Title of the Plan)
                                        
                                THOMAS M. SIEBEL
                      CHAIRMAN AND CHIEF EXECUTIVE OFFICER
                              SIEBEL SYSTEMS, INC.
                            1855 SOUTH GRANT STREET
                          SAN MATEO, CALIFORNIA 94402
                                 (650) 295-5000
 (Name, address, including zip code, and telephone number, including area code,
                             of agent for service)
                          ----------------------------

                                   Copies to:
                              ERIC C. JENSEN, ESQ.
                               COOLEY GODWARD LLP
                              3000 SAND HILL ROAD
                             BUILDING 3, SUITE 230
                       MENLO PARK, CALIFORNIA 94025-7116
                                 (650) 843-5000
                          ----------------------------
                                        
     This Registration Statement will become effective immediately upon filing
 with the Securities and Exchange Commission.  Sales of the registered
 securities will begin as soon as reasonably practicable after the effective
 date of this Registration Statement.

                        CALCULATION OF REGISTRATION FEE
==================================================================================================================================
                                                               PROPOSED MAXIMUM           PROPOSED MAXIMUM    
TITLE OF SECURITIES TO BE           AMOUNT TO BE              OFFERING PRICE PER          AGGREGATE OFFERING        AMOUNT OF 
     REGISTERED                     REGISTERED (1)                 SHARE (2)                  PRICE (1)          REGISTRATION FEE
----------------------------------------------------------------------------------------------------------------------------------
Common Stock (par value $.001)                                                                                         $1911

1991 Scopus Stock Option Plan         3,513,000                     $ 1.39                 $4,883,070 

1995 Scopus Director Plan                62,000                     $25.67                 $1,591,540
(1)  This Registration Statement shall cover any additional shares of Common
     Stock which become issuable under the plans set forth herein by reason of
     any stock dividend, stock split, recapitalization or any other similar
     transaction without receipt of consideration which results in an increase
     in the number of shares of the Company's outstanding Common Stock.
(2)  Calculated solely for the purposes of this offering under Rule 457(h)
     promulgated under the Securities Act of 1933, as amended (the "Securities
     Act"), on the basis of the price at which the options may be exercised.
     The price per share and aggregate offering price is based upon the weighted
     average exercise price pursuant to Rule 457(h) of the Securities Act, of
     the options assumed as follows:

     Options to purchase 62,000 shares of Siebel Systems, Inc. Common Stock
     issued pursuant to the 1995 Director Option Plan at an average exercise
     price of $25.67 per share.

     Options to purchase 3,513,000 shares of Siebel Systems, Inc. Common Stock
     issued pursuant to the 1991 Stock Option Plan at an average exercise price
     of $1.39 per share.

                                       2.
The shares registered hereunder will be issued upon the exercise of stock
options assumed by Siebel Systems, Inc., a Delaware corporation (the
"Registrant"), pursuant to that certain Agreement and Plan of Merger and
Reorganization among the Registrant, Syracuse Acquisition Sub, Inc. and Scopus
Technology, Inc ("Scopus"), dated March 1, 1998.  These options were originally
granted to directors of Scopus under Scopus' 1995 Director Option Plan and to
employees and consultants under Scopus' 1991 Stock Option Plan.

                                       3.
PART II

ITEM 3.  INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE.

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

     (a) The Registrant's Annual Report on Form 10-K for the year ended December
31, 1997 (File No. 0-20725), including all material incorporated by reference
therein;

     (b) The Registrant's Quarterly Report on Form 10-Q for the quarter ended
March 31, 1998 (File No. 0-20725), including all material incorporated by
reference therein;

     (c) The Registrant's Current Report on Form 8-K (File No. 0-20725), dated
March 31, 1998;

     (d) The Registrant's Current Report on Form 8-K (File No. 0-20725), dated
May 19, 1998; and

     (e) The description of the Common Stock contained in the Registrant's
Registration Statement on Form 8-A (File No. 0-20725).

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

ITEM 4.  DESCRIPTION OF SECURITIES.

         Not applicable.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.

     The validity of the issuance of the Common Stock offered hereby will be
passed upon for the Company by Cooley Godward LLP ("Cooley Godward").  As of the
date of the Prospectus, certain members and associates of Cooley Godward own an
aggregate of 28,446 shares of Common Stock. In addition, James C. Gaither, a
director and the Secretary of the Company and a partner of Cooley Godward, owns
119,314 shares of Common Stock and has options to purchase 44,000 shares of
Common Stock.  Eric C. Jensen, a partner of Cooley Godward, is an Assistant
Secretary of the Company.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.

     Under Section 145 of the Delaware General Corporation Law, the Registrant
has broad powers to indemnify its directors and officers against liabilities
they may incur in such capacities, including liabilities under the Securities
Act.

     The Registrant's Certificate of Incorporation, as amended, provides for the
elimination of liability for monetary damages for breach of the directors'
fiduciary duty of care to the Registrant and its stockholders.  These provisions
do not eliminate the directors' duty of care and, in appropriate circumstances,
equitable remedies such an 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 any transaction from which the
director derived an improper personal benefit, and for payment of dividends or
approval of stock repurchases or redemptions that are unlawful under Delaware
law.  The provision does not affect a
director's responsibilities under any other laws, such as the federal securities
laws or state or federal environmental laws.

     The Registrant has entered into agreements with its directors and executive
officers that require the Registrant to indemnify such persons against expenses,
judgments, fines, settlements and other amounts actually and reasonably incurred
(including expenses of a derivative action) in connection with any proceeding,
whether actual or threatened, to which any such person may be made a party by
reason of the fact that such person is or was a director or officer of the
Registrant or any of its affiliated enterprises, provided such person acted in
good faith and in a manner such person reasonably believed to be in or not
opposed to the best interests of the Registrant and, with respect to any
criminal proceeding, had no reasonable cause to believe his or her conduct was
unlawful.  The indemnification agreements also set forth certain procedures that
will apply in the event of a claim for indemnification thereunder.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.
         Not applicable.

ITEM 8.  EXHIBITS.

EXHIBIT
NUMBER  DESCRIPTION

 4.1    Restated Certificate of Incorporation of the Registrant, as amended to
        date./1/

 4.2    Bylaws of the Registrant./2/
 
 4.3    Specimen Stock Certificate./2/

 4.4    Restated Investor Rights Agreement, dated December 1, 1995, between the
        Registrant and certain investors, as amended April 30, 1996 and June 14,
        1996./2/

 5.1    Opinion of Cooley Godward LLP./3/

23.1    Consent of KPMG Peat Marwick LLP, Independent Auditors. /3/

23.2    Consent of Cooley Godward LLP is contained in Exhibit 5.1 to this
        Registration Statement.

24.1    Power of Attorney is contained on the signature pages. /3/

99.1    Scopus Technology, Inc. 1995 Director Option Plan. /3/

99.2    Form of option agreement under the Scopus Technology, Inc. 1995 Director
        Option Plan. /3/

99.3    Scopus Technology, Inc. 1991 Stock Option Plan. /3/

99.4    Form of option agreement under the Scopus Technology, Inc. 1991 Stock
        Option Plan. /3/
--------------------------------------------------------------------------------
/1/     Incorporated by reference to the Registrant's Registration Statement on
                Form S-8 (No. 333 07983), as amended.

/2/     Incorporated by reference to the Registrant's Registration Statement on
                Form S-1 (No. 333-03751), as amended.

/3/     Filed herewith.
ITEM 9.  UNDERTAKINGS.

   A.  The undersigned registrant hereby undertakes:

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

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

       (ii) To reflect in the prospectus any facts or events arising after the
       effective date of the Registration Statement (or the most recent post-
       effective amendment thereof) which, individually or in the aggregate,
       represent a fundamental change in the information set forth in the
       Registration Statement.  Notwithstanding the foregoing, any increase or
       decrease in volume of securities offered (if the total dollar value of
       securities offered would not exceed that which was registered) and any
       deviation from the low or high and of the estimated maximum offering
       range may be reflected in the form of prospectus filed with the
       Commission pursuant to Rule 424(b) if, in the aggregate, the changes in
       volume and price represent no more than twenty percent (20%) change in
       the maximum aggregate offering price set forth in the "Calculation of
       Registration Fee" table in the effective Registration Statement.

       (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 paragraphs (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 paragraphs is contained in periodic reports filed with or
furnished to the Commission by the Registrant pursuant to Section 13 or 15(d) of
the Exchange Act that are incorporated by reference in the Registration
Statement.

     (2) That, for the purpose of determining any liability under the Securities
Act, each such post-effective amendment shall be deemed to be a new Registration
Statement relating to the securities offered herein, 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 (and, where applicable, each filing of an employee benefit plan's
annual report pursuant to section 15(d) of the Exchange Act) that is
incorporated by reference in the 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.

   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 Securities and Exchange Commission
such indemnification is against public policy as expressed in the Securities Act
and is, therefore, unenforceable.  In the event that a claim for indemnification
against such liabilities (other than the payment by the Registrant of expenses
incurred or paid by a director, officer or controlling person of the Registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question 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.
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 San Mateo, State of California, on this 21st day of
May, 1998.

                                 SIEBEL SYSTEMS, INC.

                                 By:  /s/ Thomas M. Siebel
                                    ---------------------------------
                                    Thomas M. Siebel
                                    Chairman of the Board of Directors and Chief
                                    Executive Officer
POWER OF ATTORNEY

   KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears
below constitutes and appoints Thomas M. Siebel and Howard H. Graham, 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/ Thomas M. Siebel                     Chairman of the Board of                        May 21, 1998
----------------------------------------           Directors and Chief Executive
        Thomas M. Siebel                           Officer
                                                   (Principal Executive Officer)

          /s/ Howard H. Graham                     Senior Vice President Finance                   May 21, 1998
----------------------------------------           and Administration and Chief
        Howard H. Graham                           Financial Officer
                                                   (Principal Financial and
                                                   Accounting Officer)

          /s/ Eric E. Schmidt                      Director                                        May 21, 1998
----------------------------------------
        Eric E. Schmidt

          /s/ James C. Gaither                     Director                                        May 21, 1998
----------------------------------------
        James C. Gaither

          /s/ George T. Shaheen                    Director                                        May 21, 1998
----------------------------------------
        George T. Shaheen

          /s/ Charles R. Schwab                    Director                                        May 21, 1998
----------------------------------------
        Charles R. Schwab

          /s/ A. Michael Spence                    Director                                        May 21, 1998
----------------------------------------
        A. Michael Spence
EXHIBIT INDEX

EXHIBIT
NUMBER  DESCRIPTION

 4.1    Restated Certificate of Incorporation of the Registrant, as amended to
        date./1/

 4.2    Bylaws of the Registrant./2/
 
 4.3    Specimen Stock Certificate./2/

 4.4    Restated Investor Rights Agreement, dated December 1, 1995, between the
        Registrant and certain investors, as amended April 30, 1996 and June 14,
        1996./2/

 5.1    Opinion of Cooley Godward LLP./3/

23.1    Consent of KPMG Peat Marwick LLP, Independent Auditors. /3/

23.2    Consent of Cooley Godward LLP is contained in Exhibit 5.1 to this
        Registration Statement.

24.1    Power of Attorney is contained on the signature pages. /3/

99.1    Scopus Technology, Inc. 1995 Director Option Plan. /3/

99.2    Form of option agreement under the Scopus Technology, Inc. 1995 Director
        Option Plan. /3/

99.3    Scopus Technology, Inc. 1991 Stock Option Plan. /3/

99.4    Form of option agreement under the Scopus Technology, Inc. 1991 Stock
        Option Plan. /3/
--------------------------------------------------------------------------------
/1/     Incorporated by reference to the Registrant's Registration Statement on
                Form S-8 (No. 333 07983), as amended.

/2/     Incorporated by reference to the Registrant's Registration Statement on
                Form S-1 (No. 333-03751), as amended.

/3/     Filed herewith.