Renovascular hypertension is common in nonspecific aortoarteritis (Takayasu disease). The utility of percutaneous transluminal renal angioplasty in managing this disease has been reported infrequently, and technical problems in using this treatment method have not been described. We retrospectively evaluated the results of renal angioplasty in treating 33 stenoses in 20 patients. Each patient's diagnosis was based on the criteria established by the Aortitis Syndrome Research Committee of Japan. Criteria for selection of patients for angioplasty were (1) severe hypertension uncontrolled by single-drug therapy, (2) angiographic evidence of at least 70% stenosis of the renal artery with a pressure gradient of more than 20 mm Hg, and (3) a normal sedimentation rate. The transfemoral route was used to treat all 33 stenoses. Follow-up examinations included blood pressure and medication evaluation 1 day, 1 week, and 4-6 weeks after treatment, and thereafter at 6-month intervals. Technical success was obtained in 28 lesions (85%) in 17 patients (85%). All failures occurred in the presence of coexistent abdominal aortic disease and tight, proximal stenosis of the renal artery. Technical difficulties were attributed to the tough, noncompliant nature of the stenoses, which were difficult to cross and resisted repeated, prolonged balloon inflations. These patients experienced backache and a fall in systemic blood pressure during balloon inflation. In one patient, the ipsilateral renal vein was injured during angioplasty and required surgery. Clinical success was obtained in 14 (82%) of the 17 patients in whom technical success was achieved and included cure in six patients and improvement in eight others. Follow-up 1-18 months (mean, 8 months) after treatment showed restenosis in six (21%) of 28 lesions. We conclude that renal angioplasty in nonspecific arteritis is associated with technical difficulties; however, the short-term results are good and the complication rate is acceptable.