Cost-effectiveness analysis is used to compare proposed cholesterol control programs. The analysis employs estimates of such biologic variables as effect of diet on cholesterol level, stability of level, and change in morbidity with level. Sensitivity analysis identifies the biologic and behavioral uncertainties that most critically affect policy choices. At a discount rate of 5%, a cholesterol-screening program for all 10-year-old children would cost about 10,000 per year of life saved. Rescreening would not improve efficiency. Targeted screening a high-risk children could improve efficiency by 25%, but would benefit only one sixth as many people. Community-wide interventions without screening may be more efficient by a factor of 3. The cost per year of life saved is most affected by the rate of discount and the dollar cost of changing behavior, but is insensitive to stability of cholesterol rank order and to the cost of screening.