Among 38 patients with arterial hypertension I and II degree, the diastolic function of the left ventricle was studied in the course of a twelve-month treatment with Telmisartan (Micardis). Analysis of the diastolic function of the left ventricle before the treatment with telmisartan showed that in both groups of patients with respect to the control group there was a significant decrease in the maximum speed of early diastolic filling and an increase in the maximum rate of atrial filling with increasing severity of the disease.At the same time, the period of isovolumetric relaxation and the end diastolic pressure in the left ventricle increased, and the E/A and Ei/Ai ratios tended to decrease. At the end of the 12-month period of treatment with micardis, the achievement of target levels of blood pressure and normalization of diastolic function of the left ventricle were noted. Keywords: arterial hypertension, left ventricular diastolic dysfunction, micardis.