The aim of this study was to examine the effects of a slow-release formulation of Diltia-zem-a calcium channel blorker-on blood pressure, left ventricular mass and diastolic functions in patients with essential hypertension. The study was carried out in 20 patients (10 female, 10 male) with a mean age of 53.9+2.2 [37-70] who had mild to moderate essential hypertension. A slow release formu¬lation of Diltiazem 120 mg was given once or twice a day for 3 months. Using M-mode, 2-D and pulsed Doppler echocardiography left verticular functions. Left venticular end-diastolic diameter, septal and posterior wall thickness, and, left venticular mass index were measured before and at the end of therapy. The results are as following; Blood pressure was decreased from 175.5+2.9/105.5±1.5 mmHg to 145.8+2.3987.8+1.4 after treatment for 3 months. Pulse rate was not altered. As a result of significant decrea¬ses in M-mode echocardiographic parameters such as left venticular end-diastolic diame¬ter; septal and posterior wall thickness [LVIDD (mm) 48.311.2^>46.0+1.1 LVST (mm) 12.3+0.4-^10.9+0.4, LVPWT (mm) 11.2+0.4^10.4+0.3] p46.0+1.1, LVST(mm) 12.3+0.4-^10.9+0.4, LVPWT (mm) 11.2+0.4-^10.4+0.3] (p0.8710.1 p