Because some authorities have proposed blood cholesterol screening for children to prevent coronary heart disease, we reviewed published studies to estimate the potential risks and benefits of such screening. Childhood cholesterol levels are a poor predictor of high cholesterol levels in young adulthood and will be an even poorer predictor of coronary heart disease later in life. There is no evidence that blood cholesterol levels can be lowered more easily in children than in adults, and it seems unlikely that cholesterol reduction in childhood will be much more effective at preventing coronary heart disease than cholesterol reduction begun in middle age. Screening and interventions to lower blood cholesterol levels for millions of children would be expensive, could lead to labeling and family conflicts, and may cause malnutrition and increased noncardiovascular mortality. Because the benefits of cholesterol screening are unlikely to exceed these risks, we conclude that children should not be screened for high blood cholesterol levels.