In the aftermath of traumas such as combat or sexual assault, both men and women may experience similar symptoms, including post-traumatic stress disorder (PTSD). However, epidemiological studies have yielded higher rates of PTSD in women than in men in general populations, and there are also a number of gender differences in clinical presentation after trauma. Thus, in a study by the authors of patients presenting with physical trauma after interpersonal violence, women were more likely than men to have been previously assaulted, or to have sustained injury by a relative or someone known to them, but less likely to have used substances at the time of the assault or to require emergency surgery. A better understanding of the particular factors that contribute to higher rates of PTSD in women may ultimately shed light on the pathogenesis of this complex disorder. This article reviews gender differences in exposure to trauma and subsequent PTSD, emphasizing those features that characterize trauma and PTSD in women.