Understanding whether a history of psychological trauma is associated with perpetrating aggressive and violent behavior is of critical importance to public health. This relationship is especially important to study within urban areas where violence is prevalent. In this paper we examined whether a history of trauma or Post Traumatic Stress Disorder (PTSD) in inner city civilians was associated with violent behavior. Data were collected from over 1900 primary care patients at Grady Memorial Hospital in Atlanta, Georgia. Childhood trauma history was assessed with the Childhood Trauma Questionnaire (CTQ) and adult trauma history with the Traumatic Events Inventory (TEI). PTSD symptoms were measured with the PTSD Symptom Scale (PSS) and violent behaviors were measured with the Behavior Questionnaire (BQ). Using these measures we studied violent behavior in the inner city and its association with childhood or adult trauma history or PTSD. Trauma, PTSD and violence were all prevalent in this at-risk urban cohort. Perpetrating interpersonal violence was associated with a history childhood and adult trauma history, and with PTSD symptoms and diagnosis. An association between violent behavior and PTSD diagnosis was maintained after controlling for other pertinent variables such as demographics and presence of depression. Our findings point to a dysregulation of aggressive and violent behavior that may be a consequence of trauma and PTSD. These data indicate that more effective PTSD screening and treatment may help to reduce urban violence.