To elucidate the effects of an obesity control program on body composition and serum lipid levels, 31 obese elementary students (male: 25, female: 6) residing in the Gyeonggi area were evaluated and their body composition, serum total cholesterol, HDL-cholesterol, LDL-cholesterol and TG (triglyceride) were analyzed. The average age, height, weight and BMI (body mass index) were 11.52±1.00 yrs, 151.96±8.04 cm, 68.21±9.03 kg and 29.40±1.79 kg/m2 for the males, respectively, and 11.17±1.17 yrs, 147.83±5.15 cm, 65.05±10.86 kg and 29.62±3.24 kg/m2 for the females, respectively. There was a significant decrease in BMI for males (p〈0.001) and females (p〈0.05). There were also significant changes in all of the biochemical levels evaluated before and after the study. Specifically, the total cholesterol, LDL-cholesterol and TG level decreased after the obesity control program, while the HDL-cholesterol level increased after the program. These results indicate that obesity control programs do change the BMI, serum total cholesterol, HDL-cholesterol, LDL-cholesterol and TG levels in obese elementary students. Thus, obesity control programs are urgently needed to prevent degenerative disease and decrease obesity among children in elementary school.