Although beta-adrenergic blockers can significantly reduce mortality after a myocardial infarction, these agents are prescribed to only a minority of patients. Underutilization of beta blockers may be attributed, in part, to fear of adverse effects, especially in the elderly and in patients with concomitant disorders such as diabetes or heart failure. However, studies have shown that such patients are precisely the ones who derive the greatest benefit from beta blockade. Advancing age or the presence of potentially complicating disease states is usually not a justification for withholding beta-blocker therapy. With use of cardioselective agents and through careful dosing and monitoring, the benefits of beta blockers after myocardial infarction far outweigh the potential risks in most patients.