This study tested the hypothesis that male Vietnam veterans seeking inpatient treatment for PTSD (n = 228) exhibit more violent behavior compared with a mixed diagnostic group of male psychiatric inpatients without PTSD (n = 64) and a community sample of Vietnam veterans with PTSD not undergoing inpatient treatment (n = 273). Violent acts assessed included property destruction, threats without a weapon, physical fighting, and threats with a weapon. PTSD inpatients engaged in more types of violent behavior than both comparison conditions. Correlates of violence among PTSD inpatients included PTSD symptom severity and, to a lesser degree, measures of substance abuse. These findings justify routine assessment of violent behavior among inpatient with PTSD, as well as application of specialized interventions for anger dyscontrol and aggression.