September 20, 2004


Mail Stop 4-6

Mr. J. Michael Lawrie
Chief Executive Officer
Siebel Systems, Inc.
2207 Bridgepointe Parkway
San Mateo, CA 94404

Re:	Siebel Systems, Inc.
	Post-effective amendments on Forms S-3
	Filed August 24, 2004
	File Nos. 333-68041 and 333-91777

Dear Mr. Lawrie:

	This is to advise you that we have limited our review of the
above registration statements to the matters addressed in the comments
below.  No further review of the registration statements has been or
will be made.

Please understand that the purpose of our review process is to assist
you in your compliance with the applicable disclosure requirements and
to enhance the overall disclosure in your filing.  We look forward to
working with you in these respects.  We welcome any questions you may
have about our comments or on any other aspect of our review.  Feel
free to call us at the telephone numbers listed at the end of this
letter.

CONFIDENTIAL TREATMENT REQUEST
1. We are in the process of reviewing your confidential treatment
request filed August 9, 2004 (Control No. 15638) and will be issuing
our comments on such request, if any, shortly, under separate cover.
Please note that your post-effective amendments will not be declared
effective until all comments on your pending CTR have been cleared.

**	**	**

We urge all persons who are responsible for the accuracy and adequacy
of the disclosure in the filings reviewed by the staff to be certain
that they have provided all information investors require for an
informed decision.  Since the Company and its management are in
possession of all facts relating to a Company`s disclosure, they are
responsible for the accuracy and adequacy of the disclosures they have
made.

	Notwithstanding our comments, before we exercise our discretion
under Section 8(c) and declare your post-effective amendments
effective, the Company should furnish a letter acknowledging that:

?	should the Commission or the staff, acting pursuant to delegated
authority, declare the filing effective, it does not foreclose the
Commission from taking any action with respect to the filing;

?	the action of the Commission or the staff, acting pursuant to
delegated authority, in declaring the filing effective, does not
relieve the Company from its full responsibility for the adequacy and
accuracy of the disclosure in the filing; and

?	the Company may not assert this action as a defense in any
proceeding initiated by the Commission or any person under the federal
securities laws of the United States.

In addition, please be advised that the Division of Enforcement has
access to all information you provide to the staff of the Division of
Corporation Finance in connection with our review of your filing or in
response to our comments on your filing.

If you have any questions, please call Sara Kalin at (202) 942-2986 or
Mark Shuman at (202) 942-1818.  If you need further assistance, you
may contact me at (202) 942-1800.

							Sincerely,



							Barbara Jacobs
							Assistant Director

CC:	Via Facsimile
	Mr. Eric C. Jensen, Esq.
	Cooley Godward LLP
	Five Palo Alto Square
	3000 El Camino Real
	Palo Alto, CA 94306-2155
	Telephone:  (650) 843-5000
	Facsimile:   (650) 857-0663

Mr. J. Michael Lawrie
September 20, 2004
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