We investigated traumatic events, post-traumatic stress disorder (PTSD), and psychiatric comorbidity in 450 men and women entering private, hospital-based treatments for cocaine dependence. Overall prevalence of event exposure was the same for women and men; however, women were approximately five times more likely than men to be diagnosed with lifetime and current PTSD. Women experienced more PTSD than men even when exposed to the same type of event. In most subjects with PTSD, onset of the disorder preceded onset of cocaine dependence. Subjects with PTSD were more likely than those without PTSD to have additional co-occurring mental disorders. Findings from this relatively affluent, privately treated sample suggest that PTSD and cocaine dependence are related, independent of patients' resources. They further indicate that the relationship between gender and PTSD is robust across patient populations. More complex examinations of PTSD, cocaine dependence, and gender are needed to better understand these relationships and to design effective interventions.