Compelling evidence from clinical trials confirms the benefits of secondary prevention for patients with known coronary disease. Preventive therapies initiated after myocardial infarction can extend overall survival, reduce subsequent myocardial infarction, decrease the need for revascularization, and improve quality of life. All patients with atherosclerotic cardiovascular disease should be considered for lipid lowering therapy, antiplatelet agents, beta-blockers, and control of hypertension. Long-term therapy with angiotensin-converting enzyme inhibitors should be continued in patients with systolic dysfunction. Hormone replacement therapy has not been shown to benefit postmenopausal women when initiated after myocardial infarction. Smoking cessation, weight control, exercise, and appropriate diet represent important behavioral modifications.