QuickLinks -- Click here to rapidly navigate through this document

EXHIBIT 23.1

CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS

        As independent public accountants, we hereby consent to the incorporation by reference in this registration statement on Form S-3 of our report dated February 21, 2002, included in AVI BioPharma, Inc.'s Form 10-K for the year ended December 31, 2001 and to all references to our Firm included in this registration statement.

/s/ ARTHUR ANDERSEN LLP
Portland, Oregon
April 23, 2002

QuickLinks

EXHIBIT 23.1
CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS