This article reports on the results of a systematic review and meta-analysis of the effects of after-school programs (ASPs) on delinquency. Mixed results from some well-known evaluations, a wide range of modalities, and continued interest in and demand for this social intervention motivated this review. A rigorous criteria for inclusion of studies was developed, comprehensive search strategies were employed to identify eligible studies (published and unpublished), and a protocol was followed for coding of key study features. Meta-analytic techniques were used to assess the impact of ASPs on delinquency and investigate study features associated with variation in effects. Seventeen studies—based on 17 independent samples—met the inclusion criteria. All but two of the studies were multimodal, involving primary and secondary interventions. Studies could be grouped into one of the three primary intervention types: academic, recreation, and skills training/mentoring. There was evidence that ASPs had a small but nonsignificant effect on delinquency, with a weighted mean d = 0.062 (95% confidence interval: [–0.098, 0.223]). Moderator analyses indicated that not one of the intervention types was associated with a significant effect on delinquency. Nothing in the present review suggests that ASPs—of any type—should be discontinued. But business as usual does not seem in order for ASPs with a focus on delinquency prevention. Several research priorities could go some way toward addressing this, including further high-quality evaluations targeted on the three main types of ASPs and a special focus on program fidelity.