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                                                                     Exhibit 5.1

                          [Latham & Watkins Letterhead]

                                 August 2, 2001


CV Therapeutics, Inc.
3172 Porter Drive
Palo Alto, California  94304

               Re:    Issuance of 378,349 Shares of Common Stock of CV
                      Therapeutics, Inc.

Ladies and Gentlemen:

        In connection with the issuance by CV Therapeutics, Inc. (the "Company")
to Acqua Wellington North American Equities Fund, Ltd. of 378,349 shares of the
Company's common stock, par value $0.001 per share (the "Shares"), pursuant to
the registration statement on Form S-3 (File No. 333-59318) (the "Registration
Statement") filed by the Company with the Securities and Exchange Commission
under the Securities Act of 1933, as amended, a prospectus dated July 23, 2001
(the "Prospectus") and a prospectus supplement dated August 2, 2001, you have
requested our opinion with respect to the matters set forth below.

        In our capacity as your special counsel in connection with such
registration, we are familiar with the proceedings taken and proposed to be
taken by the Company in connection with the authorization, issuance and sale of
the Shares. In addition, we have made such legal and factual examinations and
inquiries, including an examination of originals and copies certified or
otherwise identified to our satisfaction of such documents, corporate records
and instruments, as we have deemed necessary or appropriate for purposes of this
opinion.

        In our examination, we have assumed the genuineness of all signatures,
the authenticity of all documents submitted to us as originals, and the
conformity to authentic original documents of all documents submitted to us as
copies.

        We are opining herein as to the effect on the subject transaction only
of the General Corporation Law of the State of Delaware, and we express no
opinion with respect to the applicability thereto, or the effect thereon, of the
laws of any other jurisdiction or any other laws, or as to any matters of
municipal law or the laws of any local agencies within any state.

        Subject to the foregoing and the other matters set forth herein, it is
our opinion that as of the date hereof, the Shares are validly issued, fully
paid and nonassessable.

        We consent to your filing this opinion with a Current Report on Form 8-K
and to the reference to our firm under the caption "Legal Matters" in the
Prospectus.

                              Very truly yours,

                              /s/ Latham & Watkins