Optimer Pharmaceuticals, Inc. (NASDAQ: OPTR) today announced that the Company will present at the following investor conferences:

* BMO Capital Markets 2008 Focus on Healthcare Conference on Tuesday, August 5, 2008 at 4:00 p.m. Eastern Time at the Millennium Broadway Hotel, New York City.

* Bank of America 2008 Specialty Pharmaceuticals Conference on Thursday, August 7, 2008 at 8:00 a.m. Eastern Time at the Southampton Inn, Southampton, New York.

* 28th Annual Canaccord Adams Global Growth Conference on Wednesday, August 13, 2008 at 3:30 p.m. Eastern Time at the InterContinental in Boston.

Live audio webcasts of these presentations will be accessible on the Company’s website at www.optimerpharma.com, under the investors section. Replays of these presentations will be available at the same location for thirty days following the meeting.

About Optimer Pharmaceuticals

Optimer Pharmaceuticals, Inc. is a biopharmaceutical company focused on discovering, developing and commercializing innovative anti-infective products for the treatment of serious infections. Optimer has two late-stage anti-infective product candidates. OPT-80 is being developed for the treatment of Clostridium difficile infection, the most common hospital-acquired diarrhea. Prulifloxacin is an antibiotic being developed for the treatment of travelers’ diarrhea, a form of infectious diarrhea. Additional information can be found at http://www.optimerpharma.com.