Press Release

For Immediate Release

CORVALLIS, OR — August 3, 2009 — AVI BioPharma, Inc. (NASDAQ: AVII), a developer of RNA-based drugs, will hold a conference call to report second quarter 2009 financial results on Monday, August 10, 2009, at 9:30 a.m. Eastern time (6:30 a.m. Pacific time).

Individuals interested in listening to the live conference call may do so by dialing 800-967-7135 toll free within the United States and Canada, or 719-457-2603 for international callers.

A replay of the call will be available by dialing 888-203-1112 toll free within the U.S. and Canada or 719-457-0820 for international callers. The passcode for the replay is 4026242. In addition, a recording of the call will be available within approximately 24 hours at www.avibio.com.

About AVI BioPharma

AVI BioPharma is focused on the discovery and development of RNA-based drugs utilizing proprietary derivatives of its antisense chemistry (morpholino-modified phosphorodiamidate oligomers or PMOs) that can be applied to a wide range of diseases and genetic disorders through several distinct mechanisms of action. Unlike other RNA therapeutic approaches, AVI's antisense technology has been used to directly target both messenger RNA (mRNA) and its precursor (pre-mRNA), allowing for both up- and down-regulation of targeted genes and proteins. AVI's RNA-based drug programs are being evaluated for the treatment of Duchenne muscular dystrophy as well as for the treatment of cardiovascular restenosis through our partner Global Therapeutics, a Cook Group Company. AVI's antiviral programs have demonstrated promising outcomes in Ebola Zaire and Marburg Musoke virus infections and may prove applicable to other viral targets such as HCV or Dengue viruses. For more information, visit www.avibio.com.