Little is known about specific mechanisms linking self-regulation to sexual risk taking. The present study considered four possibilities in emerging adulthood: sexual self-restraint, consideration of future consequences, substance use, and romantic competence. Never-married young adults (N = 274), ages 18 to 24, responded to anonymous Internet surveys (60.2% female, 78.8% European American, 66.3% university students). The effects of self-regulation were primarily indirect but varied by sexual behavior, suggesting that high self-regulation limits sexual risk via high sexual self-restraint and low substance use. High regulation was linked to multiple sexual partners and high-risk practices risk via high romantic competence, high self-regulation was linked to multiple sexual partners and high risk practices.