Unwanted sexual contact within the military is an important public health concern, and is more prevalent among female as compared with male personnel. The Department of Defense (DOD) 2012 Workplace and Gender Relations Survey of Active Duty Members recently reported the overall prevalence of unwanted sexual contact within the past 12 months was 6.1% in women and 1.2% in men (Department of Defense, 2012). In a large 3-year cohort study of U.S. service members, 9.4% of women reported sexual harassment and 2.1% reported sexual assault (LeardMann et al., 2013). Among women veterans, the prevalence of military sexual trauma (MST), which includes sexual harassment and sexual assault, primarily ranges from 20%–43% (Suris & Lind, 2008). Unwanted sexual contact is an important health consideration among service women because it is highly prevalent, and has been associated with adverse mental health conditions (Boyd, Bradshaw, & Robinson, 2013; Dutra et al., 2011) and substance use (McCauley, Ruggiero, Resnick, & Kilpatrick, 2010; Resnick et al., 2012). In particular, MST has been associated with increased posttraumatic stress disorder (PTSD), depression, anxiety, and suicidal behavior among women veterans (Decker, Rosenheck, Tsai, Hoff, & Harpaz-Rotem, 2013; Kimerling, Gima, Smith, Street, & Frayne, 2007; Maguen et al., 2012; O'Brien & Sher, 2013; Turchik & Wilson, 2010). One study conducted using Department of Veterans Affairs administrative data found that women veterans with MST were eight times more likely to be diagnosed with PTSD, and over twice as likely to be diagnosed with depressive disorder, anxiety disorder, and attempted suicide or self-inflicted injury, as compared with those without MST (Kimerling et al., 2007). Some studies further indicate that among women veterans, sexual assault experienced during military service was more strongly linked to increased PTSD and depression symptoms than assault that occurs outside of military service (Himmelfarb, Yaeger, & Mintz, 2006; Suris, Lind, Kashner, & Borman, 2007). A potential rationale for this finding is that certain characteristics of the military environment, such as supervisors tolerating demeaning comments towards women, may intensify the association between sexual assault and adverse mental health (Sadler, Booth, Cook, & Doebbeling, 2003). In addition to being associated with adverse mental health, unwanted sexual contact has been linked to alcohol and substance use. Specifically, prior sexual assault can increase risk for substance use/abuse, and substance use/abuse can increase risk for sexual assault (Messman-Moore, Ward, & Zerubavel, 2013; Resnick, Walsh, Schumacher, Kilpatrick, & Acierno, 2013; Ullman, Relyea, Peter-Hagene, & Vasquez, 2013). Among the women who reported unwanted sexual contact in the 2012 DOD Workplace and Gender Relations Survey, 47% indicated that they or the offender were drinking alcohol before the incident (Department of Defense, 2012). Alcohol/substance use in the context of sexual assault is particularly concerning because it may lead to greater injury to the victim (when substances are being used by the offender; Brecklin & Ullman, 2010) and also a higher prevalence of substance use after the incident (Resnick et al., 2012), potentially as a coping mechanism by the victim (Ullman et al., 2013). One recently conducted qualitative study of U.S. service women deployed overseas indicated that being in a high-stress, sexist environment could facilitate unwanted sexual contact (Burns, Grindlay, Holt, Manski, & Grossman, 2014). In particular, women in the military may face additional gender-related stresses compared to men, such as elevated levels of stress due to sexual harassment (Vogt et al., 2011) and gender harassment (Kabat-Farr & Cortina, 2014), and greater levels of stress due to family separation and perceived loss of intimate relationships (Skopp et al., 2011). There is a lack of research, however, on the association between military and gender-related stress with unwanted sexual contact. Our objective was to examine the mental health and substance use factors that were associated with active duty service women’s experience of unwanted sexual contact since entering the military. We hypothesized that alcohol/substance use, military and gender-related stress, and adverse mental health indicators (including PTSD, suicidal ideation or attempt, psychological distress, depression, and anxiety), would be positively associated with self-report of unwanted sexual contact among active duty service women.