Coronary heart disease is the major cause of death in most industrialized countries and is increasing rapidly in many developing nations. Cardiac rehabilitation programs have evolved from predominantly exercise-based programs into comprehensive secondary prevention programs. Studies of efficacy and effectiveness of cardiac rehabilitation document reductions in mortality and improvements in clinical and behavioral outcomes beyond the improvements in morbidity and mortality already available through revascularization and effective pharmacotherapy, but cardiac rehabilitation, like many preventive measures, is under-utilized. Future research directions are outlined.