We investigated relationships among prewar, wartime, and postwar factors and posttraumatic stress disorder (PTSD) severity in a community sample of 160 former prisoners of war (POWs). Data were collected from structured clinical interviews, self-report questionnaires, and military service records. POW camp trauma was most predictive of PTSD severity, followed by a refined postwar Social Support variable: Interpersonal Connection. Prewar conduct disorder behavior was positively predictive of PTSD and negatively predictive of Interpersonal Connection. Combat exposure and age at capture were also predictive of PTSD. Prewar family closeness was not a significant predictor of PTSD but was predictive of postwar Interpersonal Connection. This study provides further empirical evidence that trauma, when sufficiently severe, is the most significant predictor of PTSD severity.