Compared to childhood and adulthood, adolescence is a time of greater risk-taking behavior, potentially resulting in serious consequences. Theories of adolescent brain development highlight the imbalance between neural circuitry for reward vs. regulation. Although this imbalance may make adolescents more vulnerable to impaired decision-making in the context of heightened arousal, not all adolescents exhibit problematic risk behavior, suggesting other factors are involved. Relatedly, parent-adolescent conflict increases in mid-adolescence, and is linked to negative outcomes like substance use related risk-taking. However, the mechanism by which parent-adolescent conflict and risk-taking are linked is still unknown. Therefore, we investigated this association using a multi-method experimental design. Parent-adolescent dyads were randomly assigned to complete a discussion task together on the topic of either the adolescent's dream vacation or an adolescent-identified conflict topic. During the task, adolescent peripheral psychophysiology was measured for later calculation of heart rate variability (HRV), an index of self-regulation. Immediately after the discussion task, adolescents completed a performance-based measure of risk-taking propensity that indexes real-world risk behaviors. We hypothesized that parent-adolescent conflict would predict greater adolescent risk-taking propensity, and that increased behavioral arousal in the context of conflict, coupled with impaired self-regulation, would explain this link. Results indicated no direct effect of parent-adolescent conflict on adolescent risk-taking propensity. However, there was a significant conditional indirect effect: lower HRV, indexing worse regulatory ability, mediated the relation between conflict and risk-taking propensity but only for adolescents exhibiting behavioral arousal during the discussion task. We discuss implications for understanding adolescent risktaking behavior.