Phil Barie, MD, MBA, FCCM, discusses his article from the April edition of Critical Connections on antibiotic prophylaxis. He addresses when this therapy is most useful as well as the consequences of overuse. Dr. Barie is professor of surgery and public health at Weill Medical College of Cornell University in New York City, and he sits on the executive committee of the Society of Critical Care Medicine. (Crit Conn 2006 Vol.5 No.2)