Promoting physical activity (PA) has become a priority because of its role in preventing childhood obesity and chronic disease. Ecological approaches that recognize the interaction between individuals and the settings in which they spend their time are currently at the forefront of public health action. Schools have been identified as a key setting for health promotion. An overview of the literature addressing the promotion of PA in schools showed that school-based strategies (elementary or high school) utilizing classroom-based education only, have not increased PA levels; with one notable exception being screen time interventions. Although evidence is sparse, active school models and environmental strategies (interventions that change policy and practice) appear to be effective for promoting PA in elementary school. There is also strong evidence for multi-component models in high school and particularly for models that incorporate a family and community component. Involving youth in the development and implementation of interventions is an emerging trend. Increases in physical activity levels in school-based trials have been modest but important in the context of childhood obesity and sedentary lifestyles. School initiatives need to be supported and reinforced in other community settings. Health professionals are a key champion in the community because of their role and credibility. Health professionals can lend support to school-based efforts by; 1. asking about and emphasizing the importance of, PA with patients, 2. encouraging family-based activities, 3. supporting local schools to adopt an ‘active school’ approach and, 4. advocating for support and sustain evidence-based and promising PA models within schools.