Consistency of measures of a prosocial personality and prosocial moral judgment over time, and the interrelations among them, were examined. Participants and friends' reports of prosocial characteristics were obtained at ages 21-22, 23-24, and 25-26 years. In addition, participants' prosocial judgment was assessed with interviews and with an objective measure of prosocial moral reasoning at several ages. Reports of prosocial behavior and empathy-related responding in childhood and observations of prosocial behavior in preschool also were obtained. There was interindividual consistency in prosocial dispositions, and prosocial dispositions in adulthood related to empathy/sympathy and prosocial behavior at much younger ages. Interview and objective measures of moral reasoning were substantially interrelated in late adolescence/early adulthood and correlated with participants' and friends' reports of a prosocial disposition.