With a sample of 414 tenth-grade students (53% girls) from the Northeastern United States, the unique mediating roles that different dimensions of best friendship quality play in linking relational victimization and psychosocial maladjustment were examined. For both boys and girls, relational victimization was found to predict higher levels of internalizing behaviors directly and through partial mediation by greater conflict and weaker feelings of help within adolescents' best friendships. Increased conflict also partially mediated the association between relational victimization and higher levels of externalizing behaviors. Together, the results provide support for the significance of broader peer group functioning on both dyadic relationships and individual functioning.