Coronary heart disease is the most severe form of disease caused by atherosclerosis; and there is a strong relationship between serum lipid concentrations and atherosclerosis. By decade of life, means, standard deviations and selected percentiles were calculated according to sex for serum concentrations of total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglyceride in 69,563 Koreans. The prevalence of dyslipoproteinemias which were related to high risk of coronary heart disease were assessed. The mean concentrations of serum total cholesterol and LDL-C in the Korean population were 5.02 mmol/l and 3.00 mmol/l. The 75th and 90th percentile concentrations of total cholesterol were 5.59 mmol/l and 6.24 mmol/l. The mean concentrations of serum triglyceride and HDL-C were 1.58 mmol/l and 1.30 mmol/l. The hyperlipoproteinemia type IV (4.8%) was the most frequent, followed by Type IIa (4.6%), hypoalphalipoproteinemia (3.3%), and type IIb (0.2%). According to the National Cholesterol Education Program Adult Treatment Panel II, 4.1% of Korean adults needed the initial drug therapy and 10.8% the initial dietary therapy for hypercholesterolemia. The age and sex-specific treatment guidelines for hypercholesterolemia would make it possible that early intervention could be applied to atherosclerosis in Korean adults.