As filed with the Securities and Exchange Commission on October 11, 2001
                                                        Registration No. 333-___
================================================================================
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

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

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      Under
                           The Securities Act of 1933

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

                                THERASENSE, INC.
             (Exact name of Registrant as specified in its charter)
                             -----------------------

           Delaware                                           94-326737
(State or other jurisdiction of                            (I.R.S. Employer
 incorporation or organization)                         Identification Number)

                                TheraSense, Inc.
                              1360 South Loop Road
                            Alameda, California 94502
                                 (510) 749-5400
   (Address, including zip code, and telephone number, including area code, of
                    Registrant's principal executive offices)
                             -----------------------

                                 1997 STOCK PLAN

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

                                  W. Mark Lortz
                      President and Chief Executive Officer
                                TheraSense, Inc.
                              1360 South Loop Road
                            Alameda, California 94502
                                 (510) 749-5400
            (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)
                             -----------------------

                                    Copy to:
                             Karen A. Dempsey, Esq.
                        Wilson Sonsini Goodrich & Rosati
                            Professional Corporation
                                   One Market
                         Spear Street Tower, Suite 3300
                             San Francisco, CA 94105
                                 (415) 947-2000
                             -----------------------

                         CALCULATION OF REGISTRATION FEE



        ====================================================================================================================
                                                                     Proposed Maximum   Proposed Maximum      Amount of
                                                    Amount to be      Offering Price        Aggregate       Registration
        Title of Securities to be Registered         Registered        Per Share (1)     Offering Price          Fee
        --------------------------------------------------------------------------------------------------------------------
                                                                                                
        Common Stock $ .001 par value
        Issuable under:

        1997 Stock Plan                               5,789,715           $19.00          $110,004,585        $27,501.15
        ====================================================================================================================


(1) Estimated pursuant to Rule 457(a) under the Securities Act of 1933, as
amended, solely for the purpose of calculating the registration fee based upon
the initial price at which our common stock was sold to the public on October
11, 2001.
================================================================================



                                THERASENSE, INC.
                       REGISTRATION STATEMENT ON FORM S-8

                                     PART II

                 INFORMATION REQUIRED IN REGISTRATION STATEMENT

Explanatory Note
----------------

          This Registration Statement on From S-8 is being filed for the
purpose of registering 5,789,715 shares of the Registrant's Common Stock to be
issued in the future upon the exercise of options under the Registrant's 1997
Stock Plan (the "1997 Plan").

ITEM 3.       INCORPORATION OF DOCUMENTS BY REFERENCE.

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

              (a) TheraSense's Registration Statement on Form S-1 (File No.
333-64456) filed pursuant to Rule 424(b) under the Securities Act of 1933, as
amended (the "Securities Act"), declared effective on October 11, 2001.

              (b) The description of the Registrant's common stock which is
contained in the Registrant's Registration Statement on Form 8-A declared
effective by the Commission on October 11, 2001 pursuant to Section 12 of the
Securities Exchange Act of 1934, as amended (the "Exchange Act"), and any
description of any securities of the Registrant which is contained in any
registration statement filed after the date hereof under Section 12 of the
Exchange Act, including any amendment or report filed for the purpose of
updating any such description.

          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 to this Registration Statement which indicates that
all securities offered hereby have been sold or which deregisters all securities
remaining unsold, shall be deemed to be incorporated by reference in this
Registration Statement and to be a part hereof from the date of filing of such
documents.

ITEM 4.       DESCRIPTION OF SECURITIES.

           The class of securities to be offered is registered under Section
12(g) of the Exchange Act.

ITEM 5.       INTERESTS OF NAMED EXPERTS AND COUNSEL.

           Various legal matters with respect to the validity of the Common
Stock issued and sold under the 1997 Stock Plan will be passed upon for us by
Wilson Sonsini Goodrich & Rosati, P.C., San Francisco, California. An investment
partnership comprised of some current and former members of Wilson Sonsini
Goodrich & Rosati and one current member of Wilson Sonsini Goodrich & Rosati,
beneficially own an aggregate of 34,153 shares of the Registrant's Common Stock.
These shares have an aggregate value of $648,907.00.

                                      II-1



ITEM 6.       INDEMNIFICATION OF DIRECTORS AND OFFICERS.

       Section 145 of the Delaware General Corporation Law permits a corporation
to include in its charter documents, and in agreements between the corporation
and its directors and officers, provisions expanding the scope of
indemnification beyond that specifically provided by the current law. Article
VIII of our Amended and Restated Certificate of Incorporation provides for the
indemnification of directors to the fullest extent permissible under Delaware
law. Article VI of our Amended and Restated Bylaws provides for the
indemnification of officers, directors and third parties acting on our behalf if
such person acted in good faith and in a manner reasonably believed to be in and
not opposed to our best interest, and, with respect to any criminal action or
proceeding, the indemnified party had no reason to believe his or her conduct
was unlawful.

       We have entered into indemnification agreements with our directors and
executive officers, in addition to indemnification provided for in our charter
documents, and we intend to enter into indemnification agreements with any new
directors and executive officers in the future.

       We intend to purchase and maintain insurance on behalf of any person who
is or was a director or officer against any loss arising from any claim asserted
against him or her and incurred by him or her in any such capacity, subject to
certain exclusions.

ITEM 7.       EXEMPTION FROM REGISTRATION CLAIMED.

       Not applicable.

ITEM 8.       EXHIBITS.

     Exhibit
     Number                       Description of Document
    ---------    --------------------------------------------------------------

        4.1*       1997 Stock Plan

        5.1        Opinion of Wilson Sonsini Goodrich & Rosati, Professional
                   Corporation.

        23.1       Consent of Independent Accountants.

        23.2       Consent of Counsel (contained in Exhibit 5.1).

        24.1       Power of Attorney (see page S-1).
--------------------------------------------------------------------------------

* Incorporated by Reference to Exhibit 10.1 of the Registrant's Registration
Statement on Form S-1 (Registration No. 333-64456) declared effective by the
Commission on October 11, 2001.

                                      II-2



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 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 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 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 law, the Registrant's Amended and Restated
Certificate of Incorporation, Amended and Restated Bylaws, indemnification
agreements, 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 matter has 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.

                                      II-3



                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, as amended, the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Alameda, State of California, on October 11, 2001.

                                      By:  /s/ W. Mark Lortz
                                           ---------------------------------
                                           W. Mark Lortz
                                           President and Chief Executive Officer

                                POWER OF ATTORNEY

     Each person whose signature appears below constitutes and appoints W. Mark
Lortz, Charles T. Liamos and Robert D. Brownell jointly and severally, his or
her attorneys-in-fact, each with the power of substitution, for him or her in
any and all capacities, to sign any amendments to this Registration Statement on
Form S-8 and to file the same, with exhibits thereto and other documents in
connection therewith, with the Securities and Exchange Commission, hereby
ratifying and confirming all that each of said attorney-in-fact, or his
substitute or substitutes, may do or cause to be done by virtue hereof.

     Pursuant to the requirements of the Securities Act of 1933, as amended,
this Registration Statement of Form S-8 has been signed by the following persons
in the capacities and on the dates indicated.



                   Signature                                       Title                             Date
-------------------------------------------      -------------------------------------      -------------------
                                                                                      
 /s/ W. Mark Lortz                               President, Chief Executive Officer and     October 11, 2001
------------------------------------------       Chairman of the Board (Principal
W. Mark Lortz                                    Exective Officer)

 /s/ Charles T. Liamos                           Chief Financial Officer and Vice           October 11, 2001
------------------------------------------       President (Principal Financial Officer
Charles T. Liamos                                and Financial Officer)

/s/ Ephraim Heller                               Director                                   October 11, 2001
------------------------------------------
Ephraim Heller

/s/ Annette J. Campbell-White                    Director                                   October 11, 2001
------------------------------------------
Annette J. Campbell-White

/s/ Mark J. Gainor                               Director                                   October 11, 2001
------------------------------------------
Mark J. Gainor

/s/ Ross A. Jaffe, M.D.                          Director                                   October 11, 2001
------------------------------------------
Ross A. Jaffe

/s/ Michael McNamara                             Director                                   October 11, 2001
------------------------------------------
Michael McNamara

/s/ Robert R. Momsen                             Director                                   October 11, 2001
------------------------------------------
Robert R. Momsen

/s/ Richard P. Thompson                          Director                                   October 11, 2001
------------------------------------------
Richard P. Thompson


                                      S-1



                                INDEX TO EXHIBITS

    Exhibit
     Number                       Description of Document
--------------   ---------------------------------------------------------------
      4.1*       1997 Stock Plan
      5.1        Opinion of Wilson Sonsini Goodrich & Rosati, Professional
                 Corporation.
      23.1       Consent of Independent Accountants.
      23.2       Consent of Counsel (contained in Exhibit 5.1).
      24.1       Power of Attorney (see page S-1).
--------------------------------------------------------------------------------

* Incorporated by Reference to Exhibit 10.1 of the Registrant's Registration
Statement on Form S-1 (Registration No. 333-64456) declared effective by the
Commission on October 11, 2001.

                                      -2-