In this paper, I review an issue that is an urgent challenge in the development field-the effectiveness of after-school programs for preventing school-age youth violence in vulnerable settings in Latin American and the Caribbean. These programs have proliferated in the region and include sports, recreation, music, tutoring, and other focused activities. Given their popularity and because they target known risk factors for violence (such as drop-out from school, poor academic performance, lack of motivation, too much idle time, low quality and quantity of adult supervision, and social isolation), it is critical to examine empirically whether they can be effective prevention strategies. Unfortunately, most rigorous trials of after-school interventions to prevent youth violence have been conducted in developed countries, with far fewer in Latin America. In this review, a broad range of databases was searched systematically. Only six studies in five Latin American and Caribbean countries were identified. Reported results indicate at least some benefits for youth behavior, although not across all youth. Additional concerns regarding how these programs are implemented and whether specific components can be tied to violence prevention are noted. The need for more rigorous evaluation of these programs is noted.