The International Diabetes Federation consensus proposed an ethnically specific criteria of waist circumference (WC) for central obesity, but, the nationwide definition is still debated in Korea. For the detection of the optimal WC cutoff value, the nonadipose components of the metabolic syndrome (MS) were defined by modification of revised 2003 Rotterdam consensus as having two or more risk factors such as hypertension, hyperglycemia, and dyslipidemia without consideration of abdominal obesity. By using receiver-operating characteristic (ROC) curve analysis, cutoff points of WC and visceral fat area (VFA) for prediction of MS were 80 cm and 53.1 cm(2). WC cutoff points corresponding to VFA >53.1 and 100 cm(2) were 73.3 and 77.8 cm. The sensitivity and specificity of currently used value of WC 88 cm were 41.9 and 91.5%, suggesting that it could be too high in Korean population. Central obesity defined as WC >80 cm was significantly associated with nonadipose components of MS after adjustment for age, BMI, cholesterol, triglycerides, fasting insulin, and free testosterone levels. Central obesity with WC of >80 cm predicted the presence of nonadipose MS (odds ratio 16.6; 95% confidence interval (CI) 6.5-42.6). It was also significant (odds ratio 14.7; 95% CI 3.4-64.3) when we applied the WC value of 70 cm instead of 80 cm. In conclusion, WC of 80 and 70 cm could be appropriate cutoff points to identify the MS and visceral adiposity in Korean women with polycystic ovary syndrome (PCOS), respectively. Therefore, PCOS women with a WC over 70 cm should be closely monitored for the development of MS.