For a five year period 70 patients with myocardial infarction were followed up in order establish the length of the temporary incapacity for work. The chronic coronary insufficiency and cardiac failure were taken into consideration and in all patients bicycle ergometric examinations were carried out. The results show that the basic criterion for restored working capacity is the functional state of the myocardium (stage of chronic coronary insufficiency and degree of cardiac failure). The patients are classified into three groups according to the functional classification of the New York Cardiological Association. Of the patients followed up 88.57% fully restored their working capacity, the other 11.43% remained disabled. The mean length of the temporary disablement of the patients who restored their working capacity was 174 days. The use of non-invasive methods for examination of the cardiovascular system in polyclinical conditions is of basic importance for evaluation of patients' working capacity.