Lipoprotein (a) concentrations in sera were determined on 536 healthy reference children and adolescents aged 8-19 years from Zagreb, Croatia. The frequency distribution showed that 20.4% boys and girls had lipoprotein (a) concentrations above 0.3 g/L what is considered as a cut-off value for the increased risk of early atherosclerosis. The results of correlation studies and factor analysis support the concept that the concentrations of lipoprotein (a) could be an independent risk factor and therefore may have a great value in the prediction of atherosclerosis early in life.