This paper is a clinical discussion of post-traumatic stress disorder and violence, particularly as it applies to the Vietnam Post-Traumatic Stress Syndrome. In the first section, the syndrome is described as the sudden onset of explosive rage and unprovoked violence with little or no warning, accompanied by a drastic change in personality. It is noted that, when substance abuse is involved, it is believed that the drug tends to lower the epileptic threshold thereby exacerbating both the onset and intensity of unprovoked rage. The organic aggressive syndrome is described as being associated with certain types of brain lesions, and as possibly originating from prenatal, neonatal, or postnatal factors as well as from brain injury sustained later in life. The diagnostic criteria for the Organic Personality Syndrome are outlined in detail. In the second section, the specific characteristics of the Vietnam Post-Traumatic Stress Syndrome are described. It is stated that, while Vietnam had fewer recorded incidents of acute combat stress than World War II or Korea, it has a far greater legacy of delayed and chronic disorders after the soldiers have returned to civilian life. As victims of their clinical and diagnostic tools clinicians have overlooked the full scope of the Vietnam Post-Traumatic Stress Syndrome. References are included. (TE)