The purpose of this study was to evaluate the effectiveness of the KidShape intervention program on improving psychosocial factors, body composition, and physical fitness among overweight youth. KidShape focuses on three main components: healthful eating habits, physical activity, and psychosocial factors. Ultimately, the program is designed to improve the overall quality of life for families by providing effective pediatric weight management programs for overweight children and knowledge of healthy practices for parents. This study examined the impact a 9-week curriculum-based intervention program on the overall health of overweight youth, ages 6-14. KidShape aims to provide learning opportunities that empower youth to feel better about themselves both physically and mentally as a result of increased physical activity. Three cohorts of at-risk youth participated in the 9-week KidShape program over the span of a year. Data from three cohorts of KidShape participants were collected and analyzed. A self-report questionnaire was used to assess participants' perceptions of their quality of life at baseline and post-intervention. Dartmouth COOP charts measured various aspects of health including feelings and attitudes about physical and psychosocial well-being. Additionally, each participant's body composition was determined using a hand-held bioelectrical impedance with both pre and post test measures recorded. The Harvard Step Test for Elementary School Children was used to measure cardio-respiratory endurance. Participants completed the step test prior to beginning the program and also at its conclusion. Twenty-seven percent of the participants were classified as having “poor” cardio-respiratory health at the beginning of the study. Sixty percent were rated as “average” and thirteen percent were “good.” Only 7 percent of the participants had a body fat of less than 30 percent. Sixty percent had a body fat between 30 and 39 percent while 33 percent measured 40 or over. Dependent t tests indicated significant improvement at the conclusion of the program with increases in physical efficiency indices and decreases in body fat percentages. Items that measured psychosocial factors provided insight into participants' perception of their physical abilities, social support, and academic abilities. Dependent t tests concluded there were significant changes in perceptions of how well they performed in school and their ability level in physical activity. No significance was found in their emotional status or feeling of being supported socially. Results of this study provide suggestions and guidelines for after school programs for overweight and obese youth.Keyword(s): exercise/fitness/physical activity, obesity issues, youth-at-risk