Adolescents may engage in risk behaviors that jeopardize their futures. Although adolescent risk-taking has long been attributed to faulty decision making, surprisingly little research has directly examined this link. This study examined the role of deliberative decision making (the tendency to consider options and consequences before making a decision) and social contextual variables (parenting and friend influences) in alcohol and drug use, risky sex, and delinquency. Participants were 7,748 adolescents (50% female) in grades 7-11 from the Add Health dataset (M age=14.87, SD=1.54). Hierarchical regression analyses revealed that deliberative decision making and contextual variables were associated with risk behavior concurrently and 1year later. Furthermore, deliberative decision making interacted with social contextual variables in some models, indicating that deliberative decision making may be especially important in certain contexts. These findings suggest that both cognitive and social factors need to be considered to explain adolescents' decisions to engage in risk behavior.