Peer relationships, particularly friendships, have been theorized to contribute to how children and adolescents think about social and moral issues. The current study examined how young adolescent best friends (191 dyads; 53.4 % female) reason together about multifaceted social dilemmas and how their reasoning is related to friendship quality. Mutually-recognized friendship dyads were videotaped discussing dilemmas entailing moral, social-conventional and prudential/pragmatic issues. Both dyad members completed a self-report measure of friendship quality. Dyadic data analyses guided by the Actor-Partner Interdependence Model indicated that adolescent and friend reports of friendship qualities were related to the forms of reasoning used during discussion. Friends who both reported that they could resolve conflicts in a constructive way were more likely to use moral reasoning than friends who reported that their conflict resolution was poor or disagreed on the quality of their conflict resolution. The findings provide evidence for the important role that friendship interaction may play in adolescents’ social and moral development.