Many factors contribute to the decline in physical activity (PA) observed during adolescence. We used an ecological framework to review 30 publications of PA interventions published between 1977 and 2009 targeting youth aged 12-18 years (19 PA interventions). We included studies that measured a primary outcome of PA and also examined intervening variables. Most studies targeted the intrapersonal and environmental domains. The body of literature on PA interventions in youth suggests the importance of targeting ecological domains beyond the individual level. Future investigations should be theory-based and include analysis of mediators across ecological domains in order to identify the most effective combination of factors to promote PA in youth.