Between January 1, 1985 and January 1, 1988, 104 patients with arterial hypertension and renal artery stenosis were treated by percutaneous transluminal angioplasty (PTA). The procedure was justified by the resistance of hypertension to other treatments in 50 patients with atheromatous stenosis and 38 patients with fibrodysplasic stenosis. In the remaining 16 patients, who had severe atheroma, PTA was made necessary by ischaemic renal failure. Out of 52 PTAs (including 2 bilateral in one stage) performed in atheroma patients without renal failure, 48 (92 per cent) were immediate technical successes. In 44 patients arterial pressure measurements after 7.5 months (2-24) showed cure in 6 cases (13 per cent), improvement in 29 cases (66 per cent) and failure in 9 cases (21 per cent). Control arteriography of 40 arteries showed success in 28 cases (70 per cent), residual stenosis in 9 (22 per cent) and restenosis in 3 cases (8 per cent) (2 secondary successes of PTA). In patients with fibrodysplastic stenosis, 42 PTAs (4 bilateral) resulted in immediate angiographic success in 81 per cent. In 34 patients arterial pressure measurements after 8.2 months (2-35) showed cure in 2 cases (65 per cent), improvement in 10 cases (29 percent) and failure in 2 cases. Angiography of 34 arteries showed success in 31 (91 per cent) and restenosis in 3 (2 bypasses). In 13 of the 16 patients with renal failure, the renal function was stabilized by PTA, but 5 patients needed surgery and 2 were put on chronic dialysis. It is concluded that the immediate and medium term success rates of renal angioplasty confirm the value of this recanalization procedure in fibrodysplasia and atheroma.