Exercise tests were applied in 59 patients with coronary heart disease and angina pectoris of effort to screen the effective antianginal doses of inderal, anapriline and obsidan. The mean effective single dose of inderal was established to constitute 80 mg (from 40 to 200 mg). In the course of screening the effective antianginal doses of beta-adrenoblockers, it was demonstrated that one should not be guided by the negative chronotropic effect of the drugs, since it was of low informative value. As regards the intensity and duration of the antianginal effects, they were alike both after propranolol treatment given in a single dose and in courses. During individual screening of the effective antianginal doses of the drugs under comparison, no differences were found in the effects of inderal, anapriline and obsidan on the exercise tolerance, although some of the patients responded to higher doses of anapriline as compared to inderal. The drugs were established to exert a comparatively short-term antianginal action. In view of this fact it is desirable to administer the drugs four times a day in the majority of cases.