EXHIBIT 5.1

                                 July 30, 1997

Cardima, Inc.
47266 Benicia Street
Fremont, CA 94538

        REGISTRATION STATEMENT ON FORM S-8
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Ladies and Gentlemen:

        We have examined the Registration Statement on Form S-8 (the 
"Registration Statement") filed by you with the Securities and Exchange 
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Commission (the "Commission") on July 30, 1997, in connection with the 
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registration under the Securities Act of 1933, as amended, of a total of 
3,250,000 shares of your Common Stock (the "Shares") reserved for issuance under
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the 1997 Employee Stock Purchase Plan, the 1993 Stock Option Plan, as amended 
through May 2, 1997, and the 1997 Directors' Stock Option Plan. As your counsel 
in connection with this transaction, we have examined the proceedings taken and 
are familiar with the proceedings proposed to be taken by you in connection with
the sale and issuance of the Shares.

        It is our opinion that upon conclusion of the proceedings being taken or
contemplated by us, as your counsel, to be taken prior to the issuance of the 
Shares, and upon completion of the proceedings being taken in order to permit 
such transactions to be carried out in accordance with the securities laws of 
the various states where required, the Shares when issued and sold in the manner
described in the Registration Statement will be legally and validly issued, 
fully paid and non-assessable.

        We consent to the use of this opinion as an exhibit to the Registration
Statement and further consent to the use of our name wherever appearing in the 
Registration Statement, including the Prospectus constituting a part thereof,
and in any amendment thereto.

                                        Very truly yours,

                                        VENTURE LAW GROUP
                                        A Professional Corporation

                                        /s/ Venture Law Group