Analyses of data from a random sample of 1,259 sexually active adolescents revealed that substance use was associated with increased sexual risk taking on 2 occasions of intercourse (lst intercourse ever and lst intercourse with most recent partner), even after controlling for demographic, experiential, and dispositional confounders. Within-persons analyses yielded similar results, indicating that adolescents who used substances, on 1 of the 2 occasions, reported higher levels of risk taking on the occasion when substances were used than on the no-substance-use occasion. However, substance use was both more common and more strongly linked to risk taking among White than Black adolescents, suggesting that White adolescents are at greater risk of negative consequences related to substance use proximal to intercourse.