Many U.S. military women are exposed to unwanted sexual contact during military service, which can have important implications for mental health. Using data from the 2008 Department of Defense Survey of Health Related Behaviors, we employed multiple logistic regression methods to examine whether unwanted sexual contact was associated with stress, screening positive for mental disorders, or substance use, among active duty service women. The sample included 7,415 female military personnel, of whom 13.4% reported unwanted sexual contact (including any touching of genitals) since entering the military. After adjusting for potentially confounding variables, factors independently associated with unwanted sexual contact included military-related stress (adjusted odds ratio [AOR] = 2.44), family/personal life-related stress (AOR = 1.78), and gender-related stress (AOR = 1.98) in the past 12 months. In addition, screening positive for depression, anxiety, posttraumatic stress disorder, or psychological distress, and suicidal ideation or attempt were associated with unwanted sexual contact (AOR = 1.57-2.11). For drug/alcohol use, only misuse of tranquilizers/muscle relaxers (past 12 months) was associated with report of unwanted sexual contact (AOR = 1.35). Given the prevalence of unwanted sexual contact and corresponding adverse health outcomes in this sample of active duty women, strategies to create military structural/cultural changes and reduce gender-related stress and sexism are needed.