OBJECTIVES: To assess the prevalence rate of dyslipidemia and the level of related factors in adolescents groups in Seoul and Yangpyong area. METHODS: Design; School based survey during May-Jun 1996 in Seoul and Yangpyong county. Subject; 2,453 boys and girls, aged 13 to 19 years; 1,137 Seoul and 1,316 Yangpyong county. Main Outcome Measures; Prevalence rates of raised serum total cholesterol, triglycerides, LDL-cholesterol, decreased HDL-cholesterol, obesity, and levels of energy intake and expenditure RESULTS: Energy intake and fat intake of boys were higher than those of girls and they were higher in Seoul. Energy expenditure per day of boys was bigger than that of girls too. Prevalence rate of obesity was higher in boys of Seoul(15.2%) and girls in Yangpyong county(14.0%). Serum lipid profiles(total cholesterol, triglycerides, LDL-cholesterol) were higher among girls and all prevalence rates of dyslipidemia were higher in boys in Seoul and in girls in Yangpyong county. Especially, girls(29.1%) in Yangpyong had raised serum cholesterol level(> or =170 mg/dl). In contrast, boys in Seoul had higher level of decreased HDL-cholesterol(46.8%) compared to Yangpyong(23.6%). The relationships between serum lipid profiles and relative weights and sex are highly significant. And the relationship between triglycerides and energy intake is significant(p=0.038). But, the associations between serum lipid profiles and energy expenditure had borderline significances. CONCLUSIONS: Hypercholesterolemia rates in girls were higher. Obesity prevalence rate was highest in boys of Seoul. Relative weight and sex are significantly related to lipid profiles. Therefore, Korea is in need of preventive strategies for different obesity and gender groups.