Using data from a common cross-site protocol administered at study enrollment, in this article we examine key characteristics of 2,729 participants in the Women, Co-Occurring Disorders and Violence Study (WCDVS), including demographics, physical health, mental health, substance abuse, trauma experiences, parenting status, and past history of service use. These data are important because they represent the first federal initiative that addresses the significant lack of appropriate services for women with co-occurring substance use and mental health disorders who have experienced trauma. Study findings reveal a very vulnerable population with extensive histories of abuse and substantial physical and mental health service needs. Data suggest a pressing need for increased availability of physical and mental health services capable of serving the complex needs of women with co-occurring disorders and histories of interpersonal violence (physical and/or sexual abuse). Equally important are funding strategies to support needed services. (Contains 4 tables and 1 figure.)