The present study was undertaken to determine the prevalence of hyperlipidemia and to find out the possible impact of serum lipid profiles on other cardiovascular risk factors in Yonchon County, Korea. Population-based cross-sectional study by random cluster sampling of registered residents over 30 years of age was performed. Out of the 3804 subjects scheduled for the survey, 2520 underwent the actual examination. The prevalence of hypercholesterolemia (serum cholesterol > or = 240 mg/dl) was only 1.2%, whereas that of hypertriglyceridemia (serum triglyceride > or = 250 mg/dl) was as high as 11.3%. The serum levels of cholesterol, triglyceride and HDL cholesterol correlated with anthropometric indices, body mass indices and waist hip ratios. The prevalences of diabetes and/or hypertension increased as either serum cholesterol or triglyceride level increased. In addition, the prevalence rates of obesity, impaired glucose tolerance, hypertriglyceridemia and hypercholesterolemia in its isolated form (free of the others) were much lower than overall prevalence indicating an existence of major overlap among these cardiovascular atherosclerotic risk factors in the form of multiple combinations. Central obesity was found to be an independent associated factor for the aggregation of the conditions related to the increase in cardiovascular risks. The prevalence of hypercholesterolemia in Yonchon County was substantially lower than that previously suggested, albeit that of hypertriglyceridemia was very high. We could also observe a varying degree of transition in cardiovascular risks related to insulin resistance from the rural to the urban area with rapid emergence of non-communicable diseases as a result of modernization.