Post traumatic stress disorder (PTSD) is a common mental health outcome associated with combat operations. Since October 2001, more than 1.6 million U.S. troops have deployed as part of Operation Enduring Freedom or Operation Iraqi Freedom. Current estimates for postdeployment post-traumatic stress disorder in Operation Enduring Freedom and Operation Iraqi Freedom veterans range from 5%–30%. This paper will briefly review a series of new and ongoing projects that utilize psychophysiologic assessment for patients with Operation Enduring Freedom or Operation Iraqi Freedom combat-related PTSD. Two treatment studies are supported by the Office of Naval Research, one assessment study is supported by the Veterans Health Administration, and a second assessment study is supported by the Department of Defense. Psychophysiologic reactivity is not new to combat-related PTSD, but there are new technologies that may enhance our ability to assess and understand this aspect of the condition. Papers describing the outcomes of these studies will be forthcoming.