In essential hypertension, hemodynamic changes in systolic and diastolic function acompany left ventricul hypertrophy ussualy. Both of these cardiac function can be detected with echocardiography and were measured during this study. 23 patients with moderate essential hypertension were treated with cilazapril plus small doze of diuretic (hydrochlorothiazide) once daily for 120 days. On the begining we found diastolic disfunction, but after the treatment there was a significant improvement in isovolumic relaxation time, early diastolic filling pattern and normalized left ventricular early/ atrial filling ratio. Cilazapril + diuretic combination in a dose once daily controlled blood pressure satisfactory, too. Parameters of systolic function were in the normal levels and there were no significant changes between the two determinations. Thickness of the interventricular septum and posteroinferior wall did not change significantly after 16 weeks of therapy, probably because of too short time of investigation.