Intimate partner violence (IPV) is a severe health problem associated with significant distress and impairment in women. The most common psychiatric difficulty in battered women is posttraumatic stress disorder (PTSD); however, no research to date has investigated the relative impact of the severity of IPV and IPV-related PTSD symptoms on battered women's psychosocial functioning. In a sample of 177 sheltered battered women, PTSD severity was associated with considerable psychiatric morbidity, social maladjustment, and personal and social resource loss. Moreover, PTSD severity mediated the relationship between IPV severity and psychiatric severity and loss of personal and social resources. Results highlight the need for the assessment and treatment of IPV-related PTSD in battered women's shelters. (Contains 4 tables.)