High serum homocysteine (tHcy) concentration is increasingly recognised as independent risk factor for atherosclerosis, early coronary heart disease (CHD) and other vascular diseases. It has been proved that adult cardiovascular disease begins in childhood. In the presented studies we determined concentrations of homocysteine, lipids and lipoproteins in plasma of hypercholesterolemic and normocholesterolemic children. In hypercholesterolemic children total cholesterol, LDL cholesterol, apolipoprotein B and triglycerides were significantly higher, whereas HDL cholesterol and apolipoprotein A-I were lower in comparison to the control group. Total serum homocysteine in children with positive family history for cardiovascular disease CHD(+) was significantly higher than in the control groups, and in CHD(-) group. It was respectively 7.3 micromol/1 versus 5.45 micromol/l versus 5.21 micromol/l. The results obtained in our study indicate that in hypercholesterolemic children with positive family history for CHD, the concentration of tHcy can be considered as a separate predictive risk factor for premature cardiovascular disease.