EXHIBIT 5.1

                    OPINION OF PILLSBURY MADISON & SUTRO LLP

                                October 1, 1999

CardioDynamics International Corporation
6175 Nancy Ridge Drive
Suite 300
San Diego, California 92121

     Re:  CardioDynamics International Corporation Registration Statement on
          Form S-3 for Resale of 375,000 Shares of common stock

Ladies and Gentlemen:

     We have acted as counsel to CardioDynamics International Corporation, a
California corporation (the "Company"), in connection with the registration for
resale of 375,000 shares of common stock (the "Shares").  The Shares are
issuable upon exercise of those certain Warrants to Purchase Common Stock dated
August 25, 1999 (the "Warrants"), as described in the Company's Registration
Statement on Form S-3 ("Registration Statement") filed with the Securities and
Exchange Commission under the Securities Act of 1933, as amended (the "Act").

     This opinion is being furnished in accordance with the requirements of Item
16 of Form S-3 and Item 601(b)(5)(i) of Regulation S-B.

     We have reviewed the Company's charter documents, the corporate proceedings
taken by the Company in connection with the original issuance of the Warrants,
and a certificate of a Company officer regarding (among other things) the
Company's receipt of consideration upon the original issuance of the Warrants.
Based on such review, we are of the opinion that the Shares, if, as and when
issued upon exercise of the Warrants in accordance with the terms of the
Warrants (including the payment of the indicated purchase price), will be duly
authorized, validly issued, fully paid and nonassessable.

     We consent to the filing of this opinion as Exhibit 5.1 to the Registration
Statement and to the reference to this firm under the caption "Legal Matters" in
the prospectus which is part of the Registration Statement.  In giving this
consent, we do not thereby admit that we are within the category of persons
whose consent is required under Section 7 of the Act, the rules and regulations
of the Securities and Exchange Commission promulgated thereunder, or Item 509 of
Regulation S-B.

This opinion letter is rendered as of the date first written above and we
disclaim any obligation to advise you of facts, circumstances, events or
developments which hereafter may be brought to our attention and which may
alter, affect or modify the opinion expressed herein.  Our opinion is expressly
limited to the matters set forth above and we render no opinion, whether by
implication or otherwise, as to any other matters relating to the Company or the
Shares.

                                 Very truly yours,

                                 /s/ Pillsbury Madison & Sutro LLP


                                  EXHIBIT 5.1