Among women and gay and bisexual men, sexual assault is associated with increased rates of sexual risk behavior and negative sexual health outcomes. Although the mechanisms of these effects are potentially myriad, the current analyses examine the role of perceived partner pressure for condomless sex in mediating the association between adult sexual assault (ASA) and recent anal or vaginal sex without a condom. In a sample of 205 young adult women and gay and bisexual men, ASA was indirectly associated with condomless anal and/or vaginal sex via perceptions of partner pressure for condomless sex, ²(1) = 5.66, p = .02, after controlling for race, age, gender and sexual identity, and relationship status. The elucidation of this relational mechanism points to several potential intervention and prevention strategies that may reduce actual and perceived pressure for sex without a condom, including strategies designed to facilitate the prioritization of health and safety over relational goals and the improvement of partner selection and perceptions of partner pressure.