Although peers' and teachers' evaluations of children's prosocial behavior and peers' sociometric ratings frequently have been used in studies of social development, the validity of young children's ratings of others has been questioned, as has that for teachers' ratings of prosocial behavior. In this study, preschoolers' ratings of peers' sociometric status and prosocial behavior, as well as teachers' ratings of children's prosocial dispositions, were obtained. These were correlated with children's naturally occurring prosocial or social behavior; ratings of prosocial behavior also were correlated with children's prosocial moral reasoning and prosocial self-attributions. Peers' sociometric ratings were positively related to children's sociability whereas prosocial ratings were related to helping (but not sharing) behavior. Teachers' ratings of prosocial behavior were not related to frequency of prosocial behaviors, but were positively related to developmentally mature moral judgments and self-reported motives.