Objective: One important factor in adolescents' development of problem alcohol use is their family environment. Yet, the mechanisms that relate parenting to youth alcohol use are not well characterized. This study employed a naturalistic laboratory-based approach to observe parenting behaviors (support, structure, criticism) and adolescents' physiological and emotional responses to parent-adolescent interactions to examine associations with adolescent alcohol use. Method: Fifty eight 10-16. year olds and their parents completed a 10. minute Parent Adolescent Interaction Task (PAIT) in which they discussed a mutually highly-rated conflict topic. Parental support, structure, and criticism were coded from the interaction. Adolescents' heart rate (HR), blood pressure (BP), reported emotions, and salivary cortisol were assessed before, during, and after the interaction. Results: Findings indicated that lower parental structure and support were associated with youth's greater diastolic BP and anger arousal in response to the PAIT. Furthermore, higher HR, systolic BP, and cortisol responses to the interaction were associated with youth's alcohol use. Conclusions: Findings suggest that heightened emotional and physiological responses to parent-adolescent conflict interactions in youth may be one pathway by which parenting is associated with adolescent alcohol use and risk for abuse. © 2011 Elsevier Ltd.