BACKGROUND: To estimate the prevalence of the metabolic syndrome in Chuncheon city in those ages 45 and over and to evaluate the association between risk factors and the risk of the metabolic syndrome. METHODS: The subject of this study included 662 adults (males 276, females 386) aged 45 years or over who lived in Chuncheon city. The metabolic syndrome was defined as having 3 or more conditions inclnding abdominal obesity, high blood pressure, low HDL cholesterol, high triglyceride, and high fasting glucose. The association between the metabolic syndrome and its life-style related factors, such as smoking, exercise, and drinking, was examined, using multiple logistic regression. RESULTS: The prevalence of the metabolic syndrome from ATP III criteria was 30.1% in men, and 37.9% in women. The prevalence increased with age in women. In men, however, the prevalence increased to 55~64 age group and then it gradually decreased. The prevalence of the metabolic syndrome from Asia-Pacific criteria was 48.2% in men, and 46.6% in women. The prevalence increased with age in men and decreased in women. The highest prevalence among the individual components of diagnostic criteria of the metabolic syndrome in men was hypertension, followed by abdominal obesity, hypertriglyceridemia, low HDL-cholesterolemia, and high fasting blood glucose. And in women, it was abdominal obesity, followed by hypertension, low HDL cholesterolemia, hypertriglyceridemia, and high fasting blood glucose. After adjusting for potential covariates, current smoker was 1.93 times at a greater risk for the metabolic syndrome than non-smokers (95% confidence interval 1.06~3.51). CONCLUSION: The prevalence of the metabolic syndrome was higher than previously reported in Korea. Further studies are strongly needed to elucidate the factors which are related to the syndrome and to develop effective prevention guidelines, especially among the elderly.