The parameters of a maximal exercise stress test, without therapy, 30 to 186 days after myocardial infarction were related to cardiac death, recurrent nonfatal infarction, coronary artery by-pass surgery, development of angina pectoris and ST segment depression during subsequent stress test in 209 patients. During a follow-up period of 9.5 to 119 months (medium 52) 12 patients died, 14 developed recurrent nonfatal myocardial infarction, 4 were submitted to coronary surgery, respectively 53 and 69 patients presented angina and ST segment depression at the first test, 23 and 33 developed them subsequently. Among the exercise parameters only the systolic blood pressure less than 140 mmHg was predictive of future mortality. Angina and ST segment depression when present at the first stress test were significantly related between them and with low heart rate, low maximal systolic blood pressure and low work load, but not with cardiac mortality, reinfarction and by-pass surgery. Our results show a low predictive value of the late maximal exercise test after a myocardial infarction. Probably that depends on evolution of coronary disease, which does not provide long-term prognostic informations.