Patients with hypertension often develop left ventricular (LV) hypertrophy and deterioration of the cardiac and endothelial functions. Recent clinical trials have shown the added benefits of angiotensin II receptor blockers in hypertensive patients. Twenty-nine patients with hypertensive heart disease (HHD) underwent echocardiography, radionuclide ventriculography and the measurement of endothelial function before and after administration of candesartan (8 mg/day). The subjects were divided into poorly controlled blood pressure (BP) (group P, n=6) and well controlled BP (group C, n=23). Endothelial function was evaluated from flow-dependent dilation, which was calculated as the percent change of the radial artery diameter during reactive hyperemia after upper arm occlusion, measured with a high-resolution ultrasound system. In group C, LV diastolic function and endothelial function were significantly (p<0.05) improved at 3 months after administration, LV systolic function and hypertrophy were significantly (p<0.05) improved after 6 months and these effects were maintained at 12 months. Even in group P, LV function, LV hypertrophy, endothelial function and brain natriuretic peptide were significantly (p<0.05) improved at 6 months after administration. In patients with HHD, candesartan improves LV systolic and diastolic function, LV hypertrophy and endothelial function within 6 months of administration, regardless of the control of BP.