Hypertension is common in patients with non-insulin-dependent diabetes mellitus and is also an early sign of diabetic nephropathy in those with insulin-dependent diabetes. Hypertension contributes to the progression of both macrovascular disease and nephropathy in patients with diabetes. Certain antihypertensive agents can adversely affect carbohydrate and lipid metabolism. Angiotensin-converting enzyme inhibitors and calcium channel blockers may slow the progression of renal complications in patients with diabetes. The pharmacologic approaches to treatment of hypertension in patients with diabetes potentially differ from those in nondiabetic persons. On the basis of a review of the recent literature related to antihypertensive therapy for patients with diabetes, we describe an empiric approach to treatment of hypertension in such patients. The proposed approach must be modified as new data from randomized clinical trials become available.