The purpose of this study was to determine the relationships between serum apolipoprotein concentration and family history of coronary or cerebral events in schoolchildren. In 269 primary schoolchildren aged 6-11 years (145 boys and 124 girls) we measured the blood concentrations of total cholesterol, apolipoproteins B and A-1, and lipoprotein(a), and questioned their parents about coronary or cerebral vascular events. Serum concentrations of apo B, A-1 and Lp(a) significantly increased with age. In children with serum cholesterol concentration > 5.18 mmol/L the concentrations of apo B, A-1, Lp(a) and apo B/apo A-1 ratio were significantly higher. The concentrations of total cholesterol, apo B, Lp(a), and apo B/apo A-1 ratio in the obese group (body weight 20% above the median body weight for age and height) differed significantly from those in the non-obese group. Serum concentrations of Lp(a) in the children who had positive family histories of coronary or cerebral events (geometric mean = 0.174 x/divided by 0.036g/L) and was significantly higher than that in the children with negative history (geometric mean = 0.086 x/divided by 0.36g/L). Family history was an independent and major contributor to high Lp(a). In evaluating children's lipid profiles, measurement of Lp(a) may help to identify children and their families at increased risk and this may facilitate the targeting of preventive measures.