Evaluated the effects of a 12-week social skills program presented to 36 nonpsychotic outpatient boys who were referred for socialization problems. Seventeen boys served as wait-list controls. Major features of this program were parent involvement, group training, demonstrated social validity for the skills taught, and demonstrated discriminative and/or convergent validity for outcome measures. Results showed a significant mean increase iii mothers' ratings of their boys' social skills as a result of treatment. Significant mean decreases in teacher ratings of aggression and withdrawal due to treatment were evident for boys without oppositional defiant disorder. Interpretations and future directions are discussed.