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                                                                     EXHIBIT 5.1

                        [COOLEY GODWARD LLP LETTERHEAD]



July 27, 2004


MannKind Corporation
28903 North Avenue Paine
Valencia, CA 91355

Ladies and Gentlemen:

You have requested our opinion with respect to certain matters in connection
with the filing by MannKind Corporation (the "Company") of a Registration
Statement on Form S-1 (the "462(b) Registration Statement") with the Securities
and Exchange Commission pursuant to Rule 462(b) of Regulation C promulgated
under the Securities Act of 1933, as amended, covering an underwritten public
offering of up to 862,500 shares (the "Shares") of the Company's common stock,
par value $.01, including 112,500 shares of the Company's common stock that may
be sold pursuant to the exercise of an over-allotment option. The Shares are to
be sold together with the shares registered pursuant to Registration Statement
No. 333-115020, which was declared effective July 27, 2004 (the "Initial
Registration Statement"). (The Initial Registration Statement, as amended,
together with the Rule 462(b) Registration Statement, is herein referred to as
the "Registration Statement.")

In connection with this opinion, we have examined and relied upon the
Registration Statement and related prospectus (the "Prospectus"), the Company's
Restated Certificate of Incorporation, as amended, and Amended and Restated
Bylaws, its form of Amended and Restated Certificate of Incorporation to be
filed prior to effectiveness of the Registration Statement and Amended and
Restated Bylaws to be effective following the closing of the offering of the
Shares in accordance with the Registration Statement and Prospectus, 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.

On the basis of the foregoing, and in reliance thereon, we are of the opinion
that the Shares, when sold and issued in accordance with the Registration
Statement and the Prospectus, will be validly issued, fully paid and
nonassessable.

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



Very truly yours,

Cooley Godward LLP


By:      /s/ Jeremy D. Glaser
     -------------------------------
          Jeremy D. Glaser

                                                                    Exhibit 23.1




            CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in this Registration Statement on
Form S-1 of MannKind Corporation filed pursuant to Rule 462(b) of the Securities
Act of 1933, as amended, of our report dated April 29, 2004 (July 22, 2004, as
to the fifth paragraph of Note 1), appearing in the Registration Statement on
Form S-1 of MannKind Corporation (File No. 333-115020), which is incorporated by
reference in this Registration Statement.

We also consent to the reference to us under the headings "Summary Financial
Data," "Selected Financial Data" and "Experts" in the Registration Statement on
Form S-1 of MannKind Corporation (File No. 333-115020), which is incorporated by
reference in this Registration Statement.


DELOITTE & TOUCHE LLP
Los Angeles, California
July 27, 2004