Long-term follow-up was obtained on 138 patients who participated in a prospective, randomized study comparing two weeks with three weeks of hospitalization following uncomplicated acute myocardial infarction. Follow-up information was available on 123 (89%) of all randomized patients. The mean follow-up period was 35 months for those patients who died and 99 months for those who survived. No differences were found between the two groups with respect to survival, cardiac-related deaths, frequency or severity of angina pectoris, subsequent myocardial infarction, incidence of congestive heart failure, number of ventricular aneurysms, or subsequent medical therapy. A significantly greater number of survivors in both groups stopped smoking and had a normal initial heart size than those who died. This long-term follow-up study further supports the conclusions of earlier short-term studies that two weeks of hospitalization is safe in patients with uncomplicated acute myocardial infarction.