Increased arterial stiffness and intima media thickness (IMT) in the common carotid artery (CCA) are related to cardiovascular risk in essential hypertension. Angiotensin II plays an important role in structural and functional changes in the vasculature. In this study, we evaluated the long-term effect of the angiotensin II receptor blocker, valsartan, on IMT, arterial stiffness, and hemodynamics in the CCA in patients with essential hypertension. A prospective 24 month study of treatment with valsartan (80-160 mg/day) was performed in 24 hypertensive patients. An ultrasound of the CCA was carried out to determine IMT, the cross-sectional distensibility coefficient (CSDC), the carotid arterial stiffness index beta, and diastolic flow velocity to systolic flow velocity ratio (Vd/Vs). Treatment with valsartan for 24 months reduced systolic and diastolic blood pressure significantly. Compared to baseline, the decrease in pulse pressure was greater after 24 months treatment than after 12 months treatment. Valsartan did not influence IMT; however, after 24 months, it caused a significant increase in CSDC and a decrease in stiffness index beta compared to baseline. These changes were not observed after 12 months of treatment. In addition, Vd/Vs, a sensitive marker of relative diastolic blood flow, increased after 24 months' treatment with valsartan. These results suggest that long-term treatment with valsartan improves vascular wall function and hemodynamics in patients with essential hypertension.