Despite substantial efforts to educate adolescents about the consequences of their risky decisions, adolescent risk behavior remains a significant social and public health problem. The goal of this research was to examine the role of individual and contextual predictors of adolescent health risk behavior and risk-taking measured in the laboratory. Specifically, I examined parent-adolescent relationships and friendships as two contextual predictors of risk, and I measured adolescent distress tolerance as an individual predictor of risk behavior in a longitudinal study of adolescents and their families. In Aim 1, I used a variable-centered approach to examine concurrent and prospective predictors of adolescent risk-taking. In Aim 2, I took a person-oriented statistical approach to the study of adolescent risk-taking by examining whether there are particular groups of adolescents with particular relationship characteristics who were most likely to engage in risky behavior, and whether these groups of adolescents would be more likely to take risks if they had low distress tolerance. Aim 1 analyses revealed that adolescents were most likely to engage in health risk behaviors when they had negative parent-adolescent relationships or positive friendships, but distress tolerance was unrelated to risk-taking. None of the predictors was related to laboratory risk behavior. Aim 2 analyses revealed that the influence of adolescents' relationships on their risk-taking behaviors depended on their ability to tolerate and manage their emotions. Among adolescents with high levels of friendship conflict, distress tolerance served as a protective factor against health risk behavior. Among high distress tolerant adolescents, those who had high parent-adolescent conflict engaged in greater risk-taking than adolescents who had high friendship conflict. Across all analyses, none of the predictors accounted for Time 2 risk behavior after accounting for Time 1 risk-taking in the models. Overall, these findings suggest that adolescents' relationship experiences and distress tolerance relate to risk-taking behaviors, even at an age when adolescents are engaging in relatively low levels of risk behavior. Future research should continue investigating predictors of risk behavior across multiple levels of analysis, with an emphasis on biological, individual, relational, and environmental factors that contribute to risk-taking.