Intimate relationships involving psychological abuse, particularly those characterized by coercive control (CC), a pattern of behaviors aimed at gaining control over one's romantic partner, have been associated with poorer mental health for victims than among victims of physical partner abuse alone (Johnson & Leone, 2005). This study investigated whether CC predicted posttraumatic stress disorder (PTSD) and depression above and beyond the effects of childhood maltreatment and frequency and severity of physical partner abuse among a sample of homeless women. This is the first known study to date to investigate the role of CC in the partner abuse experiences of homeless women. Fifty-one ethnically diverse women with a history of partner abuse victimization residing in a homeless shelter in Southwest Ontario, Canada, completed questionnaires assessing partner abuse, CC, depression, and PTSD. As predicted, CC was found to predict PTSD but not depression, after controlling for childhood maltreatment and frequency and severity of physical partner abuse. In addition, women exhibited very high rates of both PTSD and depression. The relation between CC and mental health of victims, particularly the development of PTSD, should be considered in partner abuse prevention programs and interventions. Furthermore, the high rates of psychopathology reported by the women indicate a great need for psychological aid among women residing in homeless shelters.