EXHIBIT 5.1

Falk, Shaff & Ziebell, LLP Letterhead)

October 23, 2003

Peregrine Pharmaceuticals, Inc.
14272 Franklin Avenue, Suite 100
Tustin, California 92780-7017

Re:     Registration Statement on Form S-3
        Peregrine Pharmaceuticals, Inc., Common Stock, par value $.001 per share

Ladies and Gentlemen:

We are counsel for Peregrine Pharmaceuticals, Inc., a Delaware corporation (the
"Company"), in connection with the preparation of the Registration Statement on
Form S-3 (the "Registration Statement") as to which this opinion is a part,
filed with the Securities and Exchange Commission (the "Commission") on October
24, 2003, for the offer and sale by the Company of up to 12,000,000 shares of
its common stock, $.001 par value (the "Shares").

In connection with rendering our opinion as set forth below, we have reviewed
and examined originals or copies of such corporate records and other documents
and have satisfied ourselves as to such other matters as we have deemed
necessary to enable us to express our opinion hereinafter set forth.

Based upon the foregoing, it is our opinion that:

The Shares to be issued by the Company, as covered by the Registration
Statement, when issued in accordance with the terms and conditions set forth in
the Registration Statement, will be duly authorized, validly issued, fully paid
and nonassessable.

We hereby consent to the filing of this opinion as an Exhibit to the
Registration Statement and to the reference to this firm under the caption
"Legal Matters" in the prospectus included in the Registration Statement.

Very truly yours,


/s/ FALK, SHAFF & ZIEBELL, LLP
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FALK, SHAFF & ZIEBELL, LLP