Childhood and adolescent obesity has serious medical, social, and emotional consequences. This paper describes an intervention in which behavioral strategies were combined with diet planning, nutrition education, and a strenuous physical education program in a residential summer camp for obese boys 8-18 years old. Results indicated that during the program the boys made significant improvements in body weight, skinfold thicknesses, resting systolic and diastolic blood pressures, and oxygen utilization. Behavioral strategies were used in both the teaching of exercise and weight control habits and in the daily administration of the camp.