Treatment of hypertension in patients with NIDDM should be administered with special attention not to increase insulin resistance nor to impair insulin secretion capacity. The coexisting risk for coronary artery disease and myocardial infarction should not be increased by undesired drug effects on the plasma lipoprotein profile. Late lesions of diabetes mellitus (nephropathy, neuropathy) have also to be taken into account. Consequently angiotensin converting enzyme inhibitors, if necessary combined with calcium channel blockers, should be administered first. If blood pressure is thus not sufficiently controlled, alpha-adrenergic blockers, vasodilating agents or sympatholytics may be added. Once insulin treatment is installed, or if required for other reasons (nephropathy, congestive heart failure, cardiac arrhythmia), also diuretics and beta-adrenergic blockers are indicated in antihypertensive treatment of diabetic patients.