Lipoprotein (a) [Lp(a)] is a major risk factor for cardiovascular ischemic disease. We report the association between higher levels of LP(a) and dyslipidemia. 19 children with familial hypercholesterolemia (FH), 19 with familial combined hyperlipidemia (FCHL) and 15 with poligenic hypercholesterolemia (PH) were investigated. 40 normolipidemic children were the controls. Total cholesterol (TC), triglyceride (TG) and HDL cholesterol (HDLC) were measured in serum by standard procedures. Apoprotein B (ApoB) and Apoprotein AI (ApoAI) were measured with radial immunodiffusion (Behring). Lp(a) was measured with an ELISA method (Bouty Diagnostics) with poly/monoclonal antibodies. Levels exceeding 30 mg/dl were considered as high. Odd ratio of high levels of Lp(a) in the different groups was calculated with the Mantel-Haenszel procedure and with logistic regression. 15.0% of the normolipidemic children, 47.4% of FH (OR=5.1, CI 90% 1.7, 14.5), 31.6% of FCHL (OR=2.61, CI 90% 0.8, 7.7) and 46.7% of PH (OR=4.9, CI 90% 1.6, 15.2) had high levels of Lp(a). The distribution of hyperLp(a) levels did not vary significantly between the three groups of dyslipidemic children. Nevertheless, FH children had the higher risk. Hypercholesterolaemic children had higher risk of elevated Lp(a) levels in serum. The higher risk was for FH children. These data point out to the needing of enhanced procedures for prevention of atherosclerosis in this age group.