PURPOSE: This study aimed to estimate age-and gender-specific cut points for metabolic syndrome (MS) components, including body mass index (BMI), blood pressure (BP), triglycerides, high-density lipoprotein (HDL) cholesterol, and glucose. METHODS: Data from the 1998, 2001, and 2005 Korean NHANES (National Health and Nutrition Examination Survey) were analyzed (n=4164;2,139 boys and 2,025 girls, aged 10-19 years). Height, weight, waist circumference (WC), BP, triglycerides, HDL cholesterol, and fasting glucose were measured. RESULTS: BMI over 25 kg/m2 represents the 85thP (percentile) in 17-year-old boys and the 90thP in 17-year-old girls. A level of WC higher than that of the cutoff points of Asian adults was found in the 90thP of 17-year-old boys and girls. The 90thP of boys aged 15 years old and the 95thP of 13-year-old were included in the range of systolic BP over 130 mm Hg. Over the 75thP of the group showed triglycerides greater than 110 mg/dL, (criterion of MS presented by NCEP-ATP III) and the 90thP of the group showed triglycerides greater than 150 mg/dL by IDF. An HDL cholesterol level of 40 mg/dL represents the 25thP in boys and the 10thP in girls. A glucose level greater than 110 mg/dL represents the 95thP and greater than 100 mg/dL represents the 90thP. CONCLUSION: Values of the 90thP of MS components in late adolescent boys (WC, BP, and triglycerides) and girls (WC and triglycerides) were very high and in close proximity to the diagnostic criteria of adult MS.