As part of an epidemiological study on cardiovascular risk factors among children and adolescents in Navarra, lipids and lipoproteins were analyzed in 5,829 children of both sexes. The subjects were between 4 and 17 years of age and were selected at random from the school population in our community. In this article we analyze the variations in HDL-cholesterol and cholesterol/HDL and LDL/HDL risk quotients according to age and sex. Beginning at the age of 10, the HDL decreases in both sexes, although this decrease is more evident among males and they obtain levels lower than those during early childhood. Among females older than 14 there is a slight increase. Apparently the decrease in HDL among male adolescents is due to an increase in the production of testosterone during this stage of life. Both risk quotients decrease until the children are 10 years of age, after which they increase among males and stabilize or slightly decrease among females. For this reason, scores are higher for males during the last years of adolescence. The cardiovascular lipid risk increases with age and during adolescence in higher among males and depends more on the variations in HDL than on variations in cholesterol or LDL. We believe that the best definition for cardiovascular lipid risk during the infancy or adolescents is one which is based on the risk quotients.