To explore the long-term contributions of perceived peer and parental influences on adolescent risk and protective behaviors (sexual involvement, condom use, and drug use), we assessed self-reported behaviors and perceptions of peer risk involvement and parental supervision and communication among 383 low-income, urban African Americans aged 9 to 15 years at baseline over a 4-year period. Baseline perceptions of peer sexual involvement were significantly associated with youth sexual behavior at baseline and were predictive of sexual involvement through all 4 years of follow-up. Perceived parental monitoring was inversely correlated with sexual involvement through 3 years of follow-up. Perceptions of peer condom use were associated with increased levels of condom use at baseline and through 6 months of follow-up. Positive parental communication was correlated with increased condom use. Drug use was higher among youths who perceived peers or family members to be using drugs and was inversely correlated with increased parental monitoring and supervision. Stepwise regression revealed peer and parental influences for all three behaviors. Perceptions of both peer and parental behaviors influence long-term risk and protective behaviors of adolescents. Therefore, parents should be included in adolescent risk-reduction intervention efforts. Inclusion of friends and/or changing youth perceptions of peer involvement may also be effective intervention strategies.