PURPOSE: The objectives of this study were to estimate the prevalence of obesity in adolescents; to study the association between obesity, blood pressure, and dyslipidemia; and to evaluate the superiority of waist circumference to waist/hip ratio(WHR) in central obesity. METHODS: We selected 1382 adolescents(M : F=690 : 692) aged from 11 to 18 years(mean age; boys15.0, girls 15.4) in Incheon. We measured weight, height, waist, waist/hip ratio, and blood pressure, with blood sampling to evaluate the dyslipidemia. RESULTS: The prevalence of obesity was 6.7% in boys and 6.9% in girls by body mass index(BMI). The prevalence of systolic hypertension was 15.7% in normal group, 32.4% in the overweight group, and 35.4% in the obese group by BMI. The prevalence of diastolic hypertension was 4.9% in the normal group, 6.9% in the overweight group, and 14.6% the in obese group. In boys and girls, BMI, waist circumference, and WHR were positively correlated with systolic and diastolic blood pressure. respectively. In boys, triglyceride was positively correlated with waist circumference(r=0.34, P<0.05). In boys and girls, BMI was highly correlated with obesity index(r=0.98, each), with waist circumference(r=0.89, r=0.82, respectively), and with body fat(r=0.85, r=0.89) respectively. CONCLUSION: These data suggest the importance of the screening of blood pressure in obese adolescents, with prevention and intervention of obesity since it may be the most cost-effective way of reducing the complications related with obesity.