A study of comparative antianginal efficiency of metoprolol (betaloc) and propranolol (anaprilin) in 30 patients with angina of effort, receiving single doses and courses of the treatment, demonstrated similar efficiency of the two drugs in 63.3% of the patients. In 30%, antianginal effect of metoprolol was superior to that of propranolol. Prognosis of treatment efficiency on the basis of an acute pharmacologic test was possible in 93.3% of cases with metoprolol, and in 83.3% with propranolol. The results of the acute pharmacological test help to substantiate its dose and schedule of administration.