The hypothesis is tested that individuals exposed to traumatic stress who currently have lower social support have higher rates of post-traumatic stress and associated disorders. To test this, the current prevalence of five psychiatric disorders, including post-traumatic stress, generalized anxiety, depression, alcohol abuse, and drug abuse, were studied among a random sample of veterans who served in Vietnam (N = 2,490) and a random sample of “era” veterans who did not (N = 1,972). Logistic regression was used to analyze each disorder, controlling for past combat exposure, current social status, childhood delinquency, military adjustment, and current social support. Combat exposure was the best predictor of post-traumatic stress and was also associated with anxiety and depression, but not alcohol or drug abuse. Substance abuse was associated with childhood delinquency, and the best predictor of drug abuse was illicit Army drug use. Lower social support was associated with all disorders, except drug abuse. Although the causal nexus is not clear in this case, this study suggests that future research and clinical interventions should not overlook the significance of social support among victims of traumatic stress.