More than 17% of children aged 6 to 19 years living in the United States are classified as overweight. Medical costs related to overweight and obesity were recently estimated to approximate $100 billion annually. The purpose of this systematic review was to provide the scientific evidence regarding Web-based weight management programs for overweight children and adolescents. Results suggest the potential for Web-based behavioral change programs for weight management in overweight children and adolescents. Future research should emphasize rigorous methodological adequacies, develop theory-based standardized frameworks, investigate types of interventions appropriate for boys and girls in this age group, evaluate long-term effect of interventions, and examine cost as well as clinical effectiveness.