Exhibit 23.1

            CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM


We consent to the reference to our firm under the caption "Experts" and to the
use of our report dated February 17, 2004 (except for the second paragraph of
Note 1, as to which the date is September 29, 2004) in Amendment No. 7 to the
Registration Statement (Form S-1 No. 333-111193) and related Prospectus of
Peninsula Pharmaceuticals, Inc. for the registration of 5,750,000 shares of its
common stock.


                                                       /s/ Ernst & Young LLP

Palo Alto, California

September 29, 2004