The incidence of hypertension is increased in individuals with diabetes mellitus. This is especially true in patients with type 2 diabetes. In these patients high blood pressure is common at the time of diagnosis of diabetes, but the development of diabetes is often preceded by a period during which hyperinsulinemia and insulin resistance is already present. Diabetes represents by itself a major risk of cardiovascular morbidity and mortality. This risk is considerably enhanced by the co-existence of hypertension. One of the main complications of type 2 diabetes is nephropathy, which manifests initially by microalbuminuria, then by clinical proteinuria, leading to a progressive chronic renal failure and end-stage renal disease. Microalbuminuria is considered today as an indicator of renal endothelial dysfunction as well as an independent predictor of the cardiovascular risk. During recent years a number of studies have shown that tight blood pressure control is essential in diabetic patients in order to provide maximal protection against cardiovascular events and the deterioration of renal function. Of note, there is recent evidence indicating that blockade of the renin-angiotensin system with angiotensin II antagonists has marked nephroprotective effects in patients with hypertension and type 2 diabetes, both at early and late stages of renal disease.