Youth violence is reaching epidemic levels in some parts of Latin America. It is also a top priority for the region’s policymakers, with growing investments in youth violence prevention and reduction. Yet the knowledge base on what works and what does not in terms of youth violence prevention is comparatively thin, and there is comparatively limited awareness of existing or planned impact studies. In order to fill this knowledge gap, this report assesses the state of the literature on youth violence impact assessments in 33 countries of Latin America and the Caribbean. Following a systematic review of published and unpublished articles and interviews with dozens of experts, just 18 studies were detected. And while most of these came from Brazil, Chile, Colombia and Jamaica, several large randomized controlled trials are planned or ongoing in selected Central American and Caribbean countries. Taken together, the report highlights opportunities and limitations in academic, advocacy and policy debates on youth violence prevention. It recommends the application of longer-term and stronger study designs in future research, particularly of early childhood- and family-oriented interventions. What is urgently required are more comprehensive evaluations and the development of standardized metrics to track the many dimensions of youth violence.