The current investigation identified the gender-specific prevalence of sexual harassment and assault experienced during U.S. military service and the negative mental and physical health correlates of these experiences in a sample of former reservists. We surveyed a stratified random sample of 3,946 former reservists about their experiences during military service and their current health, including depression, posttraumatic stress disorder, somatic symptoms, and medical conditions. Prevalence estimates and confidence intervals of sexual harassment and assault were calculated. A series of logistic regressions identified associations with health symptoms and conditions. Both men and women had a substantial prevalence of military sexual harassment and assault. As expected, higher proportions of female reservists reported sexual harassment (60.0% vs 27.2% for males) and sexual assault (13.1% vs 1.6% for males). For both men and women, these experiences were associated with deleterious mental and physical health conditions, with sexual assault demonstrating stronger associations than other types of sexual harassment in most cases. This investigation is the first to document high instances of these experiences among reservists. These data provide further evidence that experiences of sexual harassment and assault during military service have significant implications for the healthcare needs of military veterans.