EXHIBIT 5.1

                       OPINION OF PILLSBURY WINTHROP LLP

                                 July 31, 2001

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 1,000,000 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 1,000,000 shares of common stock (the "Shares"). The Shares were
purchased from a shareholder of the Company in two transactions on July 19, 2001
and July 31, 2001, 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 and such other documents
as we deemed appropriate in connection with the original issuance of the Shares,
and a certificate of a Company officer regarding (among other things) the
Company's receipt of consideration upon the original issuance of the Shares.
Based on such review, we are of the opinion that the Shares are 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 Winthrop LLP