One hundred and forty-one patients were examined for the correctness of the diagnosis of coronary heart diseases made on an outpatient basis and for criteria that determined the temporary disability of these patients in the course of a 4-year follow-up. The sick leaves had been given to the patients because of their complaints of pains in the left half of the chest, classified by physicians as angina pectoris. However, the diagnoses turned out questionable in almost half of the cases which accounted for 45.4% of all disability days during the period under analysis. The authors stress the necessity of a more strict approach to making the diagnosis of coronary heart disease on an outpatient basis, since erroneous diagnosis may predetermine the failure of medical measures and inflict economic damage.