Hypertension is often associated clinically with diabetes either as part of the insulin resistance syndrome or as a manifestation of renal disease. Elevated systemic blood pressure accelerates the progression of both microvascular and macrovascular complications in diabetes. Agents that interrupt the reninangiotensin system confer renoprotection via a range of hemodynamic and nonhemodynamic mechanisms. Recent clinical trials confirm that these agents confer renoprotection in type 1 and type 2 diabetic patients with early or advanced renal disease. Hypertension also appears to accelerate vascular and cardiac abnormalities in diabetes, including increased atherosclerosis, arterial stiffness, left ventricular hypertrophy and diastolic dysfunction. A number of recently published and ongoing trials are exploring the role of aggressive antihypertensive treatment with a range of antihypertensive drugs in diabetic subjects at risk of or with macrovascular disease.