Hyperlipidemia clearly is a risk factor for atherosclerotic disease in adults and very likely contributes to atherogenesis in children. The American Heart Association recommends that children with elevated plasma cholesterol or triglyceride be placed on an appropriate diet in order to reduce their risk of hyperlipidemia and possibly to reduce their risk of atherosclerotic disease when they become adults. Although the evidence does not yet support the recommendation that cholesterol and saturated fat should be reduced in the diet of all children, the public should be advised that such modification appears safe and very likely to be beneficial. Measuring plasma lipids of all children in order to prevent atherosclerotic disease probably is not cost effective. However, children of high risk families should be examined for hyperlipidemia.