Although there are extensive clinical evaluations of cardiac rehabilitation after acute myocardial infarction (AMI), no full economic evaluation is available. Patients with AMI and mild to moderate anxiety or depression, or both, while still in hospital were randomized to either an 8-week rehabilitation intervention (n = 99) or usual care (n = 102). Comprehensive costs and health-related quality of life, measured with the time trade-off preference score, were obtained in a 12-month trial, and together with survival data derived from published meta-analyses, cost-utility and cost-effectiveness of early cardiac rehabilitation were estimated. The best estimate of the incremental net direct 12-month costs for patients randomized to rehabilitation was $480 (United States, 1991)/patient. During 1-year follow-up, rehabilitation patients had fewer "other rehabilitation visits" (p < 0.0001) and gained 0.052 quality-adjusted life-year more than did the group with usual care. The cost-utility ratio was $9,200/quality-adjusted life-year gained with cardiac rehabilitation during the year of follow-up. This economic evaluation of cardiac rehabilitation does not consider the important distinctions between affordability and worth of alternative health-care services. The data provide evidence that brief cardiac rehabilitation initiated soon after AMI for patients with mild to moderate anxiety or depression, or both, is an efficient use of health-care resources and may be economically justified.