This study sought to assess the association between traditional masculine gender role ideologies and sexual risk and intimate partner violence (IPV) perpetration behaviors in young men's heterosexual relationships. Sexually active men age 18-35 years attending an urban community health center in Boston were invited to join a study on men's sexual risk; participants (N=307) completed a brief self-administered survey on sexual risk (unprotected sex, forced unprotected sex, multiple sex partners) and IPV perpetration (physical, sexual and injury from/need for medical services due to IPV) behaviors, as well as demographics. Current analyses included men reporting sex with a main female partner in the past 3 months (n=283). Logistic regression analyses adjusted for demographics were used to assess significant associations between male gender role ideologies and the sexual risk and IPV perpetration behaviors. Participants were predominantly Hispanic (74.9%) and Black (21.9%); 55.5% were not born in the continental U.S.; 65% had been in the relationship for more than 1 year. Men reporting more traditional ideologies were significantly more likely to report unprotected vaginal sex in the past 3 months (OR(adj) = 2.3, 95% CI = 1.2-4.6) and IPV perpetration in the past year (OR(adj) = 2.1, 95% CI = 1.2-3.6). Findings indicate that masculine gender role ideologies are linked with young men's unprotected vaginal sex and IPV perpetration in relationships, suggesting that such ideologies may be a useful point of sexual risk reduction and IPV prevention intervention with this population.