Previous studies have shown elevated mortality among psychiatric and substance abusing patients, including veterans with PTSD. Although early studies showed elevated deaths from external causes among Vietnam veterans in the early postwar years, more recent studies have also shown increased health problems among veterans with PTSD. This study compared mortality due to behavioral causes versus other diseases among 1,866 male veterans treated for PTSD. Death certificates obtained for 110 veterans indicated behavioral causes accounted for 62.4% of deaths, standardized mortality ratio = 3.4-5.5, including accidents (29.4%), chronic substance abuse (14.7%), and intentional death by suicide, homicide, or police (13.8%). Results suggest possible opportunities to improve outcomes of this at-risk patient population through harm reduction interventions and improved continuity of care.