OBJECTIVE To elucidate associations of age and sex with serum cholesterol and triglyceride levels and to provide for the first time percentile distribution data for pediatric lipids. METHODS A high sample of 7767 (3980 boys, 3787 girls) fasting schoolchildren, 6 to 14 years of age, were studied in Athens, Greece. RESULTS The mean cholesterol ranged from 157 to 174 mg/dL for boys and from 158 to 172 mg/dL for girls peaking at 9 years of age for both sexes. Triglyceride levels also tended to increase gradually and to peak at 11 years of age for both sexes. The high-density lipoprotein cholesterol levels were highest at 9 years of age for both sexes and the low-density lipoprotein cholesterol levels also tended to peak at 9 years of age for boys and at 8 years of age for girls. Atherogenic indices ranged from 1.54 to 1.68 for boys and 1. 51 to 1.85 for girls. CONCLUSIONS According to these findings, it could be suggested that diet changes in the Greek population, especially in children and adolescents, living in big cities is significantly influencing their total cholesterol profiles throughout the last 10 years.