Patients with diabetes mellitus may have any one of several forms of hypertension. These include essential hypertension, systolic hypertension of three varieties, the hypertension associated with diabetic nephropathy (“diabetic hypertension”), and the hypertension associated with neuropathy (supine hypertension with orthostatic hypotension). Because there are differences in the hypertensive mechanisms in each of these hypertensions, the use of antihypertensive medications should be tailored to the type of hypertension present. In this review, the rationale for treating hypertension in the diabetic will be discussed, the mechanisms of action and potential side effects of antihypertensive drugs peculiar to the diabetic will be outlined, and specific antihypertensive therapy programs based on the mechanisms involved in producing each of the hypertensions will be detailed.