Despite widespread interest in examining the role of conflict for adolescent development, researchers only rarely have examined adolescents' experiences of conflict across relationships. The present study examined how adolescents' experiences of conflict with parents and friends were linked to their social functioning. Adolescents (n = 189) and their mothers and fathers participated in semistructured discussions about areas of parent-adolescent conflict in the laboratory. In addition, adolescents reported about conflict in their best friendships, and peers reported about adolescents' social acceptance and behavior in social settings. Parent–adolescent conflict was associated with peer-reported aggression and delinquency, and friendship conflict was associated with delinquency and prosocial behavior. In addition, significant Parent–Adolescent Conflict × Friend–Adolescent Conflict interactions revealed that parent–adolescent conflict was associated with poor social functioning only when conflict with best friends was also high. The findings suggest that consideration of conflict across relationships may yield insight into the specific contexts in which conflict is associated with negative outcomes for adolescents. (PsycInfo Database Record (c) 2020 APA, all rights reserved)