As filed with the Securities and Exchange Commission on November 1, 2001
                                                      Registration No. 333-_____
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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

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

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

                          Essential Therapeutics, Inc.
             (Exact Name of Registrant as Specified in Its Charter)

               Delaware                               94-3186021
    (State or Other Jurisdiction of                  (IRS Employer
    Incorporation or Organization)              Identification Number)

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

                                1365 Main Street
                          Waltham, Massachusetts 02451
           (Address of Principal Executive Offices including Zip Code)

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

             Essential Therapeutics, Inc. 2001 Incentive Stock Plan
                            (Full Title of the Plan)

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

                 Mark B. Skaletsky                      Copy to:
                     President                   Alan C. Mendelson, Esq.
            and Chief Executive Officer             Latham & Watkins
           Essential Therapeutics, Inc.          135 Commonwealth Drive
                 1365 Main Street             Menlo Park, California 94025
           Waltham, Massachusetts 02451              (650) 328-4600
                  (781) 647-5554

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

          (Name and Address, Including Zip Code, and Telephone Number,
                   Including Area Code, of Agent for Service)

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



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                                      CALCULATION OF REGISTRATION FEE
-------------------------------------------------------------------------------------------------------------------
                                                                    Proposed         Proposed
                  Title Of                         Amount           Maximum           Maximum         Amount Of
              Securities To Be                     To Be            Offering         Aggregate      Registration
                 Registered                    Registered (1)      Price Per         Offering            Fee
                                                                   Share (2)         Price (3)
--------------------------------------------- ----------------- ----------------- ---------------- ----------------
                                                                                     
Common Stock, par value $0.001 per share       1,550,000              $3.345        $5,184,750        $1,296.19
--------------------------------------------- ----------------- ----------------- ---------------- ----------------


(1)     This Registration Statement shall also cover any additional shares of
        common stock that become issuable under the Essential Therapeutics, Inc.
        (the "Company") 2001 Incentive Stock Plan (the "Plan") by reason of any
        merger, consolidation, reorganization, recapitalization,
        reincorporation, stock dividend, dividend in property other than cash,
        stock split, liquidating dividend, combination of shares, exchange of
        shares, change in corporate structure or other transaction not involving
        the receipt of consideration that results in an increase in the number
        of outstanding shares of the Company's Common Stock.

(2)     Estimated for the purpose of calculating the registration fee pursuant
        to Rule 457(c) of the Securities Act of 1933, as amended (the
        "Securities Act"), for 1,550,000 shares based on the average ($3.345) of
        the high ($3.47) and low ($3.22) prices for the Company's Common Stock
        as reported on the Nasdaq National Market on October 31, 2001.

(3)     Estimated solely for the purpose of calculating the registration fee
        pursuant to Rule 457 of the Securities Act.

Proposed sale to take place as soon after the effective date of this
Registration Statement as options granted under the 2001 Incentive Stock Plan
are exercised.
================================================================================

                                 Total Pages 8
                            Exhibit Index on Page 8



                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

         The information called for in Part I of Form S-8 is not being filed
with or included in this Registration Statement on Form S-8 (by incorporation by
reference or otherwise) in accordance with the rules and regulations of the
Securities and Exchange Commission ("SEC").

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

        This Registration Statement covers shares of common stock, par value
$0.001 per share (the "Common Stock"), of Essential Therapeutics, Inc. (the
"Company"), that have been authorized for issuance pursuant to the Company's
2001 Incentive Stock Plan (the "Plan").

Item 3.  Incorporation of Documents by Reference
         ---------------------------------------

         The following documents filed by the Company with the SEC are
incorporated herein by reference:

        (a)     The Company's Annual Report on Form 10-K for the year ended
                December 31, 2000, filed on March 21, 2001, as amended;

        (b)     The Company's Quarterly Report on Form 10-Q for the quarter
                ended March 31, 2001, filed on May 15, 2001;

        (c)     The Company's Quarterly Report on Form 10-Q for the quarter
                ended June 30, 2001, filed on August 14, 2001;

        (d)     The Company's Current Report on Form 8-K filed with the SEC on
                March 23, 2001;

        (e)     The Company's Current Report on Form 8-K filed with the SEC on
                August 6, 2001; and

        (f) The description of the Company's Common Stock contained in Items 1
and 2 of its Registration Statement on Form 8-A filed pursuant to Section 12(g)
of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), on
March 18, 1996, and any further amendment or report filed hereafter for the
purpose of updating such description.

        In addition, all documents filed by the Company pursuant to Section
13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of this
Registration Statement and prior to the filing of a post-effective amendment
that indicates that all securities offered have been sold or that deregisters
all securities then remaining unsold, shall be deemed to be incorporated by
reference in this Registration Statement and to be a part of it from the
respective dates of filing such documents. Any statement contained in a document
incorporated or deemed to be incorporated by reference herein shall be deemed to
be modified or superseded for purposes of this Registration Statement to the
extent that a statement contained herein or in any other subsequently filed
document which also is or is deemed to be incorporated by reference herein
modifies or supersedes such statement. Any such statement so modified or
superseded shall not be deemed, except as so modified or superseded, to
constitute a part of this Registration Statement.

Item 4. Description of Securities
        -------------------------

        Not applicable.

                                       2




Item 5. Interests of Named Experts and Counsel
        --------------------------------------

        Not applicable.

Item 6. Indemnification of Directors and Officers
        -----------------------------------------

        Section 145 of the General Corporation Law of Delaware permits a
corporation to indemnify any person who was or is, or is threatened to be made a
party to any threatened, pending or completed suit or proceeding, whether civil,
criminal, administrative or investigative, by reason of the fact that he or she
is or was a director, officer, employee or agent of the Company or is or was
serving at the request of the Company as a director, officer, employee or agent
of another corporation, partnership, joint venture, trust or other enterprise,
against expenses, judgments, fines and amounts paid in settlement actually and
reasonably incurred by him in connection with such action.

        A corporation may indemnify against expenses (including attorneys' fees)
and, except for an action by or in the name of the corporation, against
judgments, fines and amounts paid in settlement as part of such suit or
proceeding. This applies only if the person indemnified acted in good faith and
in a manner he or she reasonably believed to be in the best interest of the
corporation. In addition, with respect to any criminal action or proceeding, the
person had no reasonable cause to believe his or her conduct was unlawful.

        In the case of an action by or in the name of the corporation, no
indemnification of expenses may be made for any claim, as to which the person
has been found to be liable to the corporation. The exception is if the court in
which such action was brought determines that the person is reasonably entitled
to indemnity for expenses.

        Section 145 of the General Corporation Law of Delaware further provides
that if a director, officer, employee or agent of the corporation has been
successful in the defense of any suit, claim or proceeding described above, he
or she will be indemnified for expenses (including attorneys' fees) actually and
reasonably incurred by him or her.

        Article VII of the Company's Restated Certificate of Incorporation
provides that to the fullest extent permitted by the General Corporation Law of
Delaware, a director of the Company shall not be personally liable to the
Company or its stockholders for monetary damages for breach of fiduciary duty as
a director. In addition, Article VII provides that the Company may indemnify to
the fullest extent permitted by law any person made or threatened to be made a
party to an action or proceeding, whether criminal, civil, administrative or
investigative, by reason of the fact that such person or his or her testator or
intestate is or was a director, officer or employee of the Company, or any
predecessor of the Company, or serves or served at any other enterprise as a
director, officer or employee at the request of the Company or any predecessor
to the Company.

        Article VI of the Company's Bylaws provides for the indemnification of
directors, officers, employees and other agents acting on behalf of the Company
to the fullest extent permissible under the General Corporation Law of Delaware.
Article VI of the Company's Bylaws also permits the Company to secure insurance
on behalf of any officer, director, employee or other agent against any
liability asserted against him or her and incurred by him or her in any such
capacity, or arising out of his or her status as such, whether or not the
corporation would have the power to indemnify him or her against such liability
under the provisions of the General Corporation Law of Delaware.

        The Company has entered into indemnification agreements with its
directors.

Item 7. Exemption From Registration Claimed
        -----------------------------------

        Not applicable.

                                       3



Item 8. Exhibits
        --------

        The Exhibits to this Registration Statement are listed in the Index to
Exhibits located after the signature pages.

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 of 1933, as amended (the "Securities Act");

                (ii)  To reflect in the prospectus any facts or events arising
after the effective date of this 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 this 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 end 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 a 20% change in the maximum
aggregate offering price set forth in the "Calculation of Registration Fee"
table in the effective registration statement; and

                (iii) To include any material information with respect to the
plan of distribution not previously disclosed in this Registration Statement or
any material change to such information in this Registration Statement;

provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if the
information required to be included in a post-effective amendment by those
paragraphs is contained in periodic reports filed by the registrant pursuant to
Section 13 or Section 15(d) of the Exchange Act that are incorporated by
reference in this 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 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
termination of the offering.

       (b) The registrant hereby further 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 this 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 SEC 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

                                       4



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.

                                       5



                                   SIGNATURES

     Pursuant to the requirements of the Securities Act, the Company 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 Waltham, State of Massachusetts, on October 31, 2001.

                              Essential Therapeutics, Inc.

                          By: /s/ Mark B. Skaletsky
                              ---------------------------------------
                              Mark B. Skaletsky
                              President and Chief Executive Officer

                                       6



                                POWER OF ATTORNEY

     KNOW ALL MEN BY THESE PRESENT, that each person whose signature appears
below constitutes and appoints Mark B. Skaletsky and Paul J. Mellett, and each
or any of them, his true and lawful attorneys-in-fact and agents, and each 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
SEC, 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 order to effectuate the same 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
substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

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



        Signatures                              Title                              Date
----------------------------    ---------------------------------------     ------------------
                                                                      
    /s/ Mark B. Skaletsky       Chief Executive Officer, President, and     October 31, 2001
----------------------------    Chairman of the Board of Directors
    Mark B. Skaletsky           (Principal Executive Officer)

    /s/ Donald D. Huffman       Chief Financial Officer                     October 31, 2001
----------------------------    (Principal Financial and Accounting
    Donald D. Huffman           Officer)


                                Director
----------------------------
    Richard Aldrich

                                Director
----------------------------
    Kate Bingham

                                Director
----------------------------
    Charles Newhall

    /s/ James E. Rurka          Director                                    October 31, 2001
----------------------------
    James E. Rurka

    /s/ David Schnell           Director                                    October 31, 2001
----------------------------
    David Schnell

    /s/ John P. Walker          Director                                    October 31, 2001
----------------------------
    John P. Walker


                                      7





                          INDEX TO EXHIBITS

EXHIBIT
-------

4.1                  2001 Incentive Stock Plan (1)

5.1                  Opinion of Latham & Watkins

23.1                 Consent of Ernst & Young LLP

23.2                 Consent of Latham & Watkins (included in Exhibit 5.1)

24.1                 Power of Attorney (included in the signature page to this
                     Registration Statement)



(1)      Incorporated by reference to Appendix A of the Company's  Definitive
         Proxy  Statement (File No.  000-28006) as filed with the SEC on May 18,
         2001.