The purpose of this study is to address the Healthy People 2010 obesity prevention objective. This study will test the effects of a comprehensive family weight management program on the BMI z-score of 7-12 year-old children with a BMI > 85th percentile who receive primary care in a large municipal Bronx hospital. The intervention framework will draw on social marketing theory and the transtheoretical model of behavioral change to incorporate successful obesity prevention strategies. A two-arm randomized controlled clinical trial (RCT), which will enroll (n =506) 7-12 year old children with a > 85th BMI percentile, will compare the Experimental Intensive Intervention to a Standard (Control) Intervention. The Standard Intervention will receive: 1) an initial consult, which includes an overview of lifestyle goals, 2)quarterly follow-up, 3) and a monthly newsletter. The Intensive Intervention will add: 1)12 core group modules for parents (to address roles and skills) and for children (to enhance motivation and skills and to provide physical activity), 3) Tailored support using a "toolbox" approach from community health workers as extensions of the Family Weight Management professional education staff, and 4) monthly after-core follow-up groups. The study will determine if children randomized to the Experimental Intensive Intervention will have greater improvement in BMI change (z-scores) than those randomized to the Control Standard Intervention. The study will also evaluate the effects on the Experimental Intervention on lifestyle variables and assess intervention costs. The RE-AIM evaluation will address: Reach: How many of the eligible children/ families were referred and how many of those referred actually enrolled? We will use BMI data in the computerized medical records to evaluate the proportion and the appropriateness of the referrals. Efficacy/Effectiveness: How did the Experimental intervention affect BMI (changes in z-score), and key biomarkers when followed as planned? Adoption: How acceptable were the intervention(s) to the primary care medical team and the children/families in the pediatric clinics etc? (from process measures and post intervention surveys) Implementation: How many of the intervention activities were provided as planned? Quality control measures will be used to evaluate the integrity of the intervention(s). Maintenance: How much of the intervention effect is sustainable? Individual effects will be evaluated based on the 24 month follow data. Institutional effects evaluation will include the potential to maintain services using third-party coverage.