UCLA PEERS® for Adolescents is a widely applied program among a number of social skills training programs developed over the years. We synthesized current research evidence on the PEERS program to evaluate the treatment effect on four commonly used outcome measures. 12 studies met inclusion criteria for the review and nine met the criteria for meta-analysis. Results showed moderate to large pooled effects across measures and informants in favor of the PEERS program, with the largest effect seen in social knowledge improvement and the smallest effect in the frequency of get-togethers. The heterogeneity of effects across studies were examined and the limitations of the current evidence were discussed.