Two studies were conducted to investigate interpersonal violence in Vietnam veterans with posttraumatic stress disorder (PTSD). In study one, combat veterans with PTSD reported significantly greater occurrence of violent behaviors over the past year (22 acts) versus combat veterans without PTSD (.2 acts). Combat exposure had an independent positive association with interpersonal violence. In study two, variables related to current interpersonal violent behavior in 118 PTSD combat veterans were evaluated. In rank order of importance, lower socioeconomic status, increased aggressive responding and increased PTSD severity were related to interpersonal violence. These results suggest that combat veterans with PTSD exhibit greater interpersonal violence than combat veterans without PTSD, and that there are multiple factors in this population which determine violent behavior.