Acusphere, Inc. (NASDAQ: ACUS) today announced that Dr. Richard Walovitch, Senior Vice President of Clinical Research, has resigned to pursue another opportunity. His resignation, effective January 9, 2009, follows an 11 year career with Acusphere, in which he oversaw the Company’s clinical trials for its lead product candidate, Imagify^TM (Perflubutane Polymer Microspheres) for Injectable Suspension, a cardiovascular drug for the detection of coronary artery disease, which addresses a potential $2 billion U.S. marketplace.

Said Dr. Walovitch, “I am very proud to have been associated with Acusphere’s efforts on behalf of Imagify, and our work to demonstrate its benefits to patients and physicians. As the Company awaits completion of the review by the U.S. Food and Drug Administration, now is the right time for me to move to the next phase of my career, and I’m grateful for the experience of working with my many talented colleagues at Acusphere.”

Sherri C. Oberg, President and CEO of Acusphere, said, “Rick has made many significant contributions to Acusphere’s success over the past 11 years, and we greatly appreciate his commitment to seeing this project through to its final stage. We wish him well in his next venture.”

About Acusphere, Inc.

Acusphere (NASDAQ: ACUS) is a specialty pharmaceutical company that develops new drugs and improved formulations of existing drugs using its proprietary microsphere technology. We are focused on developing proprietary drugs that can offer significant benefits such as improved safety and efficacy, increased patient compliance, greater ease of use, expanded indications or reduced cost. Our lead product candidate, Imagify^TM (Perflubutane Polymer Microspheres) for Injectable Suspension, is a cardiovascular drug for the detection of coronary artery disease, the leading cause of death in the United States, for which a New Drug Application (NDA) was submitted to the U.S. Food & Drug Administration (FDA) in April 2008 and filed in June 2008. Imagify is designed to enable ultrasound to compete more effectively with nuclear stress testing, the leading procedure for detecting coronary artery disease. It is estimated that more than 10 million procedures are done each year in the U.S. to detect coronary artery disease, the leading cause of death in the United States. The Company estimates that the potential annual U.S. market opportunity for Imagify exceeds $2 billion.