Background. Obesity and diabetes are epidemic in the predominantly minority Harlem community. To address them, a coalition of community and academic leaders tested the effectiveness of a peer-led weight loss course. Methods. The coalition developed Project HEAL: Healthy Eating, Active Lifestyles through extensive collaboration with community members and experts in nutrition, exercise, and peer education. We piloted the course in a local church and assessed its impact through pre and post course weights, self-reported behaviors and quality of life. Results. Twenty-six overweight and obese African American adults lost a mean of 4.4 pounds at 10 weeks, 8.4 pounds at 22 weeks, and 9.8 pounds at 1 year. Participants reported decreased fat consumption and sedentary hours, and improved health related quality of life. Conclusions. A peer-led, community-based course can lead to weight loss and behavior change. The minority communities most affected by obesity and diabetes may benefit from this low-cost, culturally appropriate intervention.