Adolescents engage in more risky behavior when they are with peers and show, on average, heightened susceptibility to peer influence relative to children and adults. However, individual differences in susceptibility to peer influence are not well understood. The current study examined whether the effect of peers on adolescents' risky decision making was moderated by pubertal status. Participants (58 youth, ages 11-16, 50% male, 63.9% African American) completed a computerized measure of risky decision making, once alone and once in the presence of two peers. Pubertal status was assessed using self-report. Adolescents made riskier decisions in the presence of peers, and more advanced pubertal development predicted greater risky decision making, controlling for chronological age. The effect of peer presence on risky decision making was attenuated for adolescents with more advanced pubertal development. These findings suggest that the presence of peers may override biologically based individual differences in propensity for risk taking.