EXHIBIT 99.1

                              [Versicor Letterhead]

July 6, 2001


TO OUR STOCKHOLDERS:

     Your Board of Directors has adopted a Shareholder Rights Plan (the "Plan")
and declared a distribution of rights under the Plan to stockholders of record
on July 9, 2001.

     The Plan is designed to address the problem of unilateral actions by
hostile acquirers which are calculated to deprive a corporation's board and its
stockholders of their ability to determine the future of their corporation. The
Plan was not adopted in response to any specific effort to acquire control of
Versicor Inc. (the "Company"), and we are not aware of any such effort.

     After careful consideration, your Board concluded that the Plan is a
reasonable and appropriate response to the risks posed to stockholder interests
by coercive or inadequate takeover attempts, including creeping accumulations in
the open market, partial and two-tier tender offers and other takeover attempts
that do not treat all stockholders equally. The Board believes that such
attempts, which have become commonplace in the takeover environment, are not in
the best interests of stockholders and that the Plan will enable the Board to
act more effectively in protecting stockholder values.

     The Plan does not prevent the Board from considering or accepting an offer
to acquire the Company if the Board believes the offer to be in the best
interests of the Company and its stockholders.

     A summary description of the rights is enclosed, and we urge you to read it
carefully. No action is necessary on your part.

     Similar plans have been adopted by more than 1000 major companies. The
Board believes that the adoption of the Plan is a sound and reasonable means of
preserving the long-term value of the Company for all of its stockholders. We
want to thank all stockholders for their continued support.

     If you have any questions, please contact Dov A. Goldstein, M.D., our Chief
Financial Officer, at 34790 Ardentech Court, Fremont, California 94555.

                                           Sincerely,



                                           George F. Horner III
                                           President and Chief Executive Officer





                                SUMMARY OF RIGHTS

     On June 7, 2001, the Board of Directors of Versicor Inc. (the "Company")
declared a dividend distribution of one Right for each outstanding share of
Company Common Stock to stockholders of record at the Close of Business on July
9, 2001 (the "Record Date"). Each Right entitles the registered holder to
purchase from the Company one one-hundredth of a share of Series A Junior
Participating Preferred Stock, par value $0.01 per share (the "Preferred
Stock"), at a Purchase Price of $98.00, subject to adjustment. The description
and terms of the Rights are set forth in a Stockholder Rights Agreement (the
"Rights Agreement") between the Company and American Stock Transfer & Trust
Company, as Rights Agent.

     Initially, the Rights will be attached to all Common Stock certificates
representing shares then outstanding, and no separate Rights Certificates will
be distributed. Subject to certain exceptions specified in the Rights Agreement,
the Rights will separate from the Common Stock and a Distribution Date will
occur upon the earlier of (i) 10 business days following a public announcement
that a person or group of affiliated or associated persons (an "Acquiring
Person") has acquired, or obtained the right to acquire, beneficial ownership of
15% or more of the outstanding shares of Common Stock (the "Stock Acquisition
Date"), other than as a result of repurchases of stock by the Company or certain
inadvertent actions by institutional or certain other stockholders or (ii) 10
business days (or such later date as the Board shall determine) following the
commencement of a tender offer or exchange offer that would result in a person
or group becoming an Acquiring Person. Until the Distribution Date, (i) the
Rights will be evidenced by the Common Stock certificates and will be
transferred with and only with such Common Stock certificates, (ii) new Common
Stock certificates issued after the Record Date will contain a notation
incorporating the Rights Agreement by reference, and (iii) the surrender for
transfer of any certificates for Common Stock outstanding will also constitute
the transfer of the Rights associated with the Common Stock represented by such
certificate. Pursuant to the Rights Agreement, the Company reserves the right to
require prior to the occurrence of a Triggering Event (as defined below) that,
upon any exercise of Rights, a number of Rights be exercised so that only whole
shares of Preferred Stock will be issued.

     The Rights are not exercisable until the Distribution Date and will expire
at 5:00 P.M. (Pacific time) on July 9, 2011, unless earlier redeemed or
exchanged by the Company as described below.

     As soon as practicable after the Distribution Date, Rights Certificates
will be mailed to holders of record of the Common Stock as of the Close of
Business on the Distribution Date and, thereafter, the separate Rights
Certificates alone will represent the Rights.

     Except as otherwise determined by the Board of Directors, only shares of
Common Stock issued prior to the Distribution Date will be issued with Rights.

     In the event that a Person becomes an Acquiring Person, except pursuant to
an offer for all outstanding shares of Common Stock which the independent
directors determine to be at a price which is fair and not inadequate and to
otherwise be in the best interests of the Company and its stockholders, after
receiving advice from one or more investment banking firms (a "Qualified
Offer"), each holder of a Right will thereafter have the right to receive, upon

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exercise, Common Stock (or, in certain circumstances, cash, property or other
securities of the Company) having a value equal to two times the exercise price
of the Right. The Exercise Price is the Purchase Price times the number of
shares of Common Stock associated with each Right. Notwithstanding any of the
foregoing, following the occurrence of the event set forth in this paragraph,
all Rights that are, or (under certain circumstances specified in the Rights
Agreement) were, beneficially owned by any Acquiring Person or an affiliate or
associate thereof will be null and void. However, Rights are not exercisable
following the occurrence of the event set forth above until such time as the
Rights are no longer redeemable by the Company as set forth below.

     For example, at an exercise price of $98.00 per Right, each Right not owned
by an Acquiring Person (or by certain related parties) following an event set
forth in the preceding paragraph would entitle its holder to purchase $196.00
worth of Common Stock (or other consideration, as noted above) for $98.00.
Assuming that the Common Stock had a per share value of $14 at such time, the
holder of each valid Right would be entitled to purchase 14 shares of Common
Stock for $98.00.

     In the event that, at any time following the Stock Acquisition Date, (i)
the Company engages in a merger or other business combination transaction in
which the Company is not the surviving corporation (other than with an entity
which acquired the shares pursuant to a Qualified Offer), (ii) the Company
engages in a merger or other business combination transaction in which the
Company is the surviving corporation and the Common Stock of the Company is
changed or exchanged, or (iii) 50% or more of the Company's assets or cash flow
is sold or transferred, each holder of a Right (except Rights which have
previously been voided as set forth above) shall thereafter have the right to
receive, upon exercise, common stock of the acquiring company (or in certain
circumstances, its parent) having a value equal to two times the exercise price
of the Right. The events set forth in this paragraph and in the second preceding
paragraph are referred to as the "Triggering Events."

     At any time after a person becomes an Acquiring Person and prior to the
acquisition by such person or group of 50% or more of the outstanding Common
Stock, the Board may exchange the Rights (other than Rights owned by such person
or group which have become void), in whole or in part, at an exchange ratio of
one share of Common Stock or one one-hundredth of a share of Preferred Stock (or
of a share of a class or series of the Company's preferred stock having
equivalent rights, preferences and privileges) per Right (subject to
adjustment).

     At any time until 10 business days following the Stock Acquisition Date,
the Company may redeem the Rights in whole, but not in part, at a price of $0.01
per Right (payable in cash, Common Stock or other consideration deemed
appropriate by the Board of Directors). Immediately upon the action of the Board
of Directors ordering redemption of the Rights, the Rights will terminate and
the only right of the holders of Rights will be to receive the $0.01 redemption
price.

     Until a Right is exercised, the holder thereof, as such, will have no
rights as a stockholder of the Company, including, without limitation, the right
to vote or to receive dividends. While the distribution of the Rights will not
be taxable to stockholders or to the Company, stockholders may, depending upon
the circumstances, recognize taxable income in the

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event that the Rights become exercisable for Common Stock (or other
consideration) of the Company or for common stock of the acquiring company or in
the event of the redemption of the Rights as set forth above.

     Any of the provisions of the Rights Agreement may be amended by the Board
of Directors of the Company prior to the Distribution Date. After the
Distribution Date, the provisions of the Rights Agreement may be amended by the
Board in order to cure any ambiguity, to make changes which do not adversely
affect the interests of holders of Rights, or to shorten or lengthen any time
period under the Rights Agreement. The foregoing notwithstanding, no amendment
may be made at such time as the Rights are not redeemable.

     A copy of the Rights Agreement is available free of charge from the Rights
Agent. This summary description of the Rights does not purport to be complete
and is qualified in its entirety by reference to the Rights Agreement, which is
incorporated herein by reference.



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