Subjective maximal exercise test was performed in 317 patients in the third week after an acute myocardial infarction (AMI); 78% of the total AMI population could be tested. The long-term survival was assessed on the basis of data from the exercise test. The average follow-up time was 5.7 years. Mortality increased significantly among patients with major ventricular arrhythmias and among those with a small increase in the pressure rate product (dPRP) from rest to maximal exercise. Patients with arrhythmias and those with a low dPRP constituted a high-risk group of 165 patients (52%). The probability of 5-year survival was 0.551 in this group vs. 0.783 in the others (p less than 0.001). The death rate was higher in the high-risk group than in the other patients throughout the whole observation period.