Peer- and teacher-reported prosocial behavior of 339 6th-grade (11-12 years) and 8th-grade (13-14 years) students was examined in relation to prosocial goals, self-processes (reasons for behavior, empathy, perspective taking, depressive affect, perceived competence), and contextual cues (expectations of peers and teachers). Goal pursuit significantly predicted prosocial behavior, and goal pursuit provided a pathway by which reasons for behavior were related to behavior. Reasons reflected external, other-focused, self-focused, and internal justifications for behavior; each reason was related to a unique set of self-processes and contextual cues. Associations between prosocial outcomes and sex and race (Caucasian and African American) were mediated in part by self-processes and contextual cues. The implications of studying prosocial behavior from a motivational perspective are discussed.