Sexual assault is a common and serious health issue that is underreported and has low follow-up rates. The myriad of psychological sequelae of sexual assault are well documented; however, there is a dearth of literature on the prevalence of preexisting mental health issues in survivors of sexual assault. This exploratory study compares victims seen at a sexual assault treatment center with and without preexisting self-reported mental health histories. The rates of preexisting mental illness in sexual assault victims are significant. Implications for clinical practice and research are discussed.