Postinfarction treatment trials have demonstrated that beta-blockers are beneficial after myocardial infarction (MI), significantly reducing postinfarction cardiac mortality and nonfatal reinfarction, aside from bringing about an improved quality of life. Such cardioprotective action is probably mediated by both antiarrhythmic and anti-ischemic effects of these drugs. Beta-Blockers without ISA seem to be more effective in reducing cardiac mortality than those with ISA, which is probably due to their different effects on heart rate. Patients deriving major benefit from beta-blocker therapy after MI should be "high risk," elderly, and, perhaps, hypertensive patients. The suitable duration of postinfarction beta-blocker therapy is unknown: results from recent long-term trials speak in favor of continuous postinfarction beta-blocker therapy.