Young sexual minority males are among those at highest risk for HIV infection, yet we know relatively little about the impact of sexual identity development on HIV risk. This study used cross-sectional data to investigate factors associated with HIV-related sexual risk among a sample of sexual minority males (n = 156), ages 14 to 21 years, using an extended version of the information-motivation-behavioral skills (IMB) model tailored for this population. Path analysis results indicated that the extended model predicted a sizable amount of primary and secondary sexual risk (r[squared] = 0.35 and 0.42). In addition to increasing HIV prevention information and motivation and decreasing substance use, study findings suggest that interventions with young sexual minority males should focus on sexual identity development factors including youths' attitudes toward LBGT people, sex-centered versus identity-centered development, and with specific emphasis on youth with non-male exclusive sexual orientations. (Contains 2 tables and 3 figures.)