The purpose of this study was to take a multidimensional perspective to prosocial behavior and self-regulation by analyzing longitudinal, bidirectional relations between prosocial behavior toward strangers, friends, and family members and behavioral, cognitive, and emotional dimensions of self-regulation across adolescence. Participants included reports from 500 adolescents (age Time 1 = 12, Time 2 = 14, Time 3 = 16, Time 4 = 18; 52% female, 77% European American) taking part in the Flourishing Families Project. Nine cross-lagged panel models were conducted analyzing longitudinal associations between each target of prosocial behavior and each dimension of self-regulation. Results revealed that in early adolescence, prosocial behavior toward strangers and cognitive self-regulation were bidirectionally related. Prosocial behavior toward strangers was significantly associated with cognitive self-regulation from age 12 to age 18 and cognitive self-regulation was significantly associated with prosocial behavior toward friends across adolescence. Further, behavioral and emotional self-regulation were significantly related to prosocial behavior toward family from age 12 to age 18. Gender was significantly associated with initial levels of study variables but was not significantly relate to patterns of association. Discussion focuses on how findings fit into existent theory and research.