The effects of renal revascularization on blood pressure and renal function were evaluated in 8 hypertensive patients with renal impairment and renal artery stenosis in both kidneys (6 cases) or in a solitary kidney (2 cases). Mean age was 66 +/- 7 years. The mean duration of arterial hypertension was 13 +/- 8 years. In spite of treatment with 3 antihypertensive drugs (or more in 5 cases) blood pressure values ranged from 170-90 to 260-150 mmHg. Adding captopril (in 3 cases) or minoxidil (in 1 case) resulted in control of hypertension in 1 patient and further deterioration of renal function in 2. Two patients underwent surgery after failure of percutaneous transluminal angioplasty. There were 6 revascularizations and 2 nephrectomies with contralateral revascularization. One patient died post-operatively. In the remaining 7 patients, the hypertension was controlled with one or two drugs and the renal function remained stable or improved over a mean follow-up period of 2 years. We consider that these results warrant radiological exploration in all patients, even old, with renal impairment and drug-resistant hypertension. Renal revascularization must be performed as early as possible in view of the rapid degradation of renal function under medical treatment in these patients.