The utility of cardiac rehabilitation for elderly cardiac patients is controversial, and cost, logistic barriers, and encumbering comorbidities often seem disproportionate. Many clinicians view the emphasis of cardiac rehabilitation on behavior modification and risk-factor reduction as irrelevant for very old adults and consider pure exercise programs as appropriate alternatives. The strong rationale for cardiac rehabilitation and secondary prevention is elucidated, and available corroborating data are presented. The benefits of exercise prescription in cardiac rehabilitation and synchronized risk-factor reduction are pertinent to aging and age-related heart disease, including coronary heart disease and heart failure.