Adolescence is a period of sexual experimentation. We examined psychosocial predictors of high-risk sexual behavior and condom use. The sample included 824 ninth-graders, most of whom are African American. We conducted separate analyses for whites and African Americans. Predictors included alcohol and substance use, delinquency, prosocial behaviors, and family and peer influences. We found that problem behaviors predicted high-risk sexual behavior, but the effects were stronger for white youth. We also found that friends' behaviors were more predictive than family influences, except for family conflict. In general, the models explained more variance for white youths than for African-American youths. The results suggest that problem behavior theory and social interactions theory may be most relevant for white youth and that other models may be necessary to explain high-risk sexual behavior among African-American youths.