In 1,395 patients in the age range 40-74 years participating in a double-blind trial with metoprolol in suspected acute myocardial infarction morbidity and quality of life were assessed during the first 5 years after randomization. During the first 3 months patients were given 200 mg metoprolol daily or placebo. Thereafter the two groups were treated similarly. Mortality during 5 years was 24.2% in patients originally randomized to metoprolol versus 25.7% in patients originally randomized to placebo (p > 0.2). No difference was observed regarding reinfarction rate, stroke or occurrence of bypass surgery during the 5-year follow-up. During the first 3 months 10% of patients in the metoprolol group were rehospitalized for various reasons versus 13 % in the placebo group. The corresponding figures for 5 years were 59 and 60%, respectively. Among patients surviving 5 years 84% in both groups were on some medication of which beta-blockade was the dominating one. Symptoms of chest pain, dyspnea, claudicatio, smoking habits and working capacity did not differ and neither did quality of life according to the Nottingham Health Profile. We thus conclude that morbidity and quality of life were not significantly affected 5 years after early intervention with metoprolol in patients with suspected acute myocardial infarction.