Exhibit 32.2

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Advanced Magnetics, Inc. (the “Company”) on Form 10-Q for the period ended December 31, 2004 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Michael N. Avallone, Vice President – Finance and Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

(1)The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2)The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ Michael N. Avallone

Michael N. Avallone

Vice President – Finance and Chief Financial Officer

February 10, 2005