Using a longitudinal design, we investigated the relation of childhood personality type to volunteering during adolescence. We hypothesized that participants with more adaptive personality functioning during childhood would be more likely to volunteer during adolescence and that membership in social organizations would mediate the relation of personality to volunteering during adolescence. Participants from the National Longitudinal Survey of Youth (NLSY) with complete data measures for the four time periods of study were categorized into one of three personality types during early childhood. Children assigned to the resilient personality type were more likely than children characterized by the overcontrolled and undercontrolled personality types to volunteer 8 and 10 years later in adolescence. Analyses demonstrated that the association of childhood personality to adolescent volunteering is not mediated by late-childhood membership in social institutions that may facilitate entry into volunteering. The findings are interpreted in terms of their implications for understanding personality and prosocial behavior.