High blood pressure occurs in many pregnant diabetic patients (30 to 40 p cent), and it is associated with significant impairement of fetal prognosis. Hypertension is no doubt a marker of the vascular diabetic disease, which obviates an adequate placentation. Proper antihypertensive management is necessary in those patients, but its prognostic importance is far less than is that of a perfect glycemic control. Antihypertensive therapy differs in some aspects from what is should be in non-pregnant patients: first, compounds such as angiotensin converting enzyme inhibitors, or calcium-channel blockers are not considered safe in pregnant women, whereas they are the first choice in non-pregnant diabetics. Second, over-control of blood pressure is very harmful to fetal growth, and should be carefully avoided. Finally, present literature lacks proper controlled studies, which could help in designing the best antihypertensive therapeutic strategy in pregnant diabetic patients.