This study was performed to investigate the effectiveness of nutritional education and exercise intervention on reduction and maintenance of weight. The subjects were 24 obese women whose body mass index(BMI) was over $25kg/m^2$. Nutritional education was performed once a week and swimming was done three times a week throughout this 12 week program. The subjects were recalled 1 month after the program was complete. Nutrient intakes were assessed by 24 hour recall method. Also food habits, dietary behaviors and nutritional knowledge were investigated by self-administered questionnaires before and after the weight control program and one month after completing the program. Height, weight, body composition and blood levels were measured before and after the weight control program and one month after completing the program. During the 12 weeks of the weight control program, body weight significantly decreased from an average of 69.7kg to 65.8kg and to 65.1kg after one month(p<0.05). Body fat and BMI also significantly decreased(p<0.01). Cholesterol and blood sugar levels decreased after 12 weeks and increased one month after completing the program. After taking nutritional education, the nutritional knowledge scores increased. Calcium intake significantly increased after completing the education and one month after completing the program(p<0.01). Iron intake significantly decreased from an average of 12.1g to 11.3g after completing the program and increased to 15.5g one month after completing the progrom(p<0.001). We concluded that our nutritional education and exercise program was effective for reducing and maintaining weight.