Cost-effectiveness analysis of preventive therapies are reviewed in the following categories: lipid lowering, hypertension, smoking cessation, exercise, and anticoagulation. From review of 8 analyses, cost-effectiveness of primary prevention via cholesterol lowering drugs is generally expensive, whereas that of secondary prevention generally is favorable. However, targeting by age, coexisting risk factors, and gender strongly influence results that are also sensitive to drug costs. Treatment of hypertension (5 analyses) is cost-effective in virtually all patient populations and circumstances and for a wide variety of drugs. It is more so with coexisting risk. Issues relating to compliance and drug costs are important. Smoking cessation (4 analyses) is highly cost-effective and worthwhile. However, data on recidivism are incomplete, and cessation may be more difficult to achieve in the general population versus study patients. In one analysis, an exercise program was found to be cost-effective in prevention of coronary heart disease. Anticoagulants have been analyzed in various circumstances. Their cost-effectiveness is favorable for prosthetic valves, although sensitive to imprecision in monitoring. It is also favorable for mitral stenosis in the presence of atrial fibrillation but not normal sinus rhythm. Cost-effectiveness of heparinization for prosthetic valve patients undergoing surgery is rather variable and depends on type of surgery (major versus minor) and type of valve. Many topics in anticoagulant therapy remain to be explored from a cost-effectiveness point of view.