From our review of the epidemiologic and clinical literature, we have developed recommendations for using the serum cholesterol test as a component of strategies to prevent coronary heart disease in asymptomatic adults. Total cholesterol, high-density lipoprotein, and low-density lipoprotein levels are risk factors for coronary disease and early mortality in middle-aged men. Weaker evidence suggests that hypercholesterolemia increases the risk for coronary disease in women or elderly men, or that hypertriglyceridemia increases the risk in men or women. A reduction in cholesterol levels lowers the incidence of and the mortality from coronary disease in asymptomatic, hypercholesterolemic, middle-aged men, but has not been shown to reduce overall mortality. The efficacy of treatment in women and elderly persons has not been studied. Screening and treatment plans should be individualized; a 5-year period between tests is adequate for asymptomatic, low-risk men, whereas more frequent testing is appropriate for high-risk men. Screening is optional for women and elderly persons.