A short treatment course (2-3 weeks) of calcium antagonist isoptin-retard has been tried in 20 patients with stable essential hypertension stage II-III. The treatment achieved: clinical response in the majority of the patients in the presence of minor prolongation of the atrioventricular conduction, a clear tendency to reduction of systolic, mean arterial and resting diastolic pressures. Stroke volume increased both at rest and under loading, peripheral resistance of the vessels diminished, maximum filling rate for the left ventricle increased, its peak was reached more rapidly, hemodynamic contribution of the first third diastole to left ventricular filling rose against less contribution of the left atrial systole. Thus, it is shown that isoptin-retard in a mean dose 420 mg/day demonstrates hypotensive activity and beneficial hemodynamic effects without pronounced increase in atrial-ventricular conduction in hypertensive subjects with the disease stage II-III.