Exhibit 5.1



                        [COOLEY GODWARD LLP LETTERHEAD]

March 28, 2003

Aradigm Corporation
3929 Point Eden Way
Hayward, California 94545

RE:  REGISTRATION STATEMENT ON FORM S-3

Ladies and Gentlemen:

You have requested our opinion with respect to certain matters in connection
with the filing by Aradigm Corporation (the "Company") of a Registration
Statement on Form S-3 (the "Registration Statement") with the Securities and
Exchange Commission, including a prospectus covering the offering of up to
27,281,687 shares of Common Stock, no par value, as described in the
Registration Statement (the "Shares").

In connection with this opinion, we have examined and relied upon the
Registration Statement and related Prospectus, the Company's Amended and
Restated Articles of Incorporation and Bylaws and the originals or copies
certified to our satisfaction of such records, documents, certificates,
memoranda and other instruments as in our judgment are necessary or appropriate
to enable us to render the opinion expressed below. We have assumed the
genuineness and authenticity of all documents submitted to us as copies thereof,
and the due execution and delivery of all documents where due execution and
delivery are a prerequisite to the effectiveness thereof. We have also assumed
that prior to any sale of the Shares the Company will have sufficient authorized
and unissued shares of Common Stock, the terms of offer and sale of the Shares
will have been authorized by resolutions of the Company's Board of Directors and
an appropriate prospectus supplement with respect to the Shares being sold will
have been prepared, delivered and filed in compliance with the Securities Act of
1933, as amended, and the applicable rules thereunder.

On the basis of the foregoing, and in reliance thereon, we are of the opinion
that the Shares, when issued and paid for in accordance with the Registration
Statement and the applicable prospectus supplement and authorizing resolutions,
will be validly issued, fully paid and nonassessable.

We consent to the reference to our firm under the caption "Legal Matters" in the
Prospectus included in the Registration Statement and to the filing of this
opinion as an exhibit to the Registration Statement.

Very truly yours,

Cooley Godward LLP

By: /S/ JAMIE E. CHUNG
   ----------------------------
   Jamie E. Chung