EXHIBIT 5.1

                      [LETTERHEAD OF FOLEY & LARDNER, LLP]


January 14, 2005


Alliance Pharmaceutical Corp.
4660 La Jolla Village Drive, Suite 825
San Diego, CA 92122


Re:   Alliance Pharmaceutical Corp.
      Registration Statement on Form S-8


Dear Ladies and Gentlemen:


We have acted as counsel to you (the "Company") in connection with the
preparation and filing of the above-captioned Registration Statement on Form S-8
(the "Registration Statement") under the Securities Act of 1933, as amended (the
"Act"), covering 3,400,000 shares of the Company's Common Stock, par value $.01
per share (the "Common Stock"), issuable pursuant to the 2001 Stock Option Plan
of Alliance Pharmaceutical Corp. (the "Stock Option Plan").

We have examined copies of the Certificate of Incorporation and By-laws of the
Company, each as amended to date, the Stock Option Plan, the minutes of various
meetings of the Board of Directors of the Company and the original, photostatic
or certified copies of all such records of the Company, and all such agreements,
certificates of public officials, certificates of officers and representatives
of the Company or others, and such other documents, papers, statutes and
authorities as we deemed necessary to form the basis of the opinions hereinafter
expressed. In such examination, we have assumed the genuineness of signatures
and the conformity to original documents of the documents supplied to us as
copies. As to various questions of fact material to such opinions, we have
relied upon statements and certificates of officers of the Company and others.

Based upon the foregoing, we are of the opinion that all of the Shares covered
by the Registration Statement have been duly authorized and, when issued in
accordance with the terms of the Plans, will be validly issued, fully paid and
nonassessable.

We hereby consent to your filing a copy of this opinion as an exhibit to the
Registration Statement. In giving such consent, we do not admit hereby that we
come within the category of persons whose consent is required under Section 7 of
the Act, or the rules and regulations of the Securities and Exchange Commission
thereunder.


Very truly yours,

/s/ FOLEY & LARDNER, LLP

FOLEY & LARDNER, LLP