Percutaneous transluminal angioplasty (PTA) was used to treat 109 patients with 141 renal artery stenoses, including 58 patients in whom medical management was unsuccessful. The initial success rate was 94%. Fifty-five patients had severe diffuse atherosclerosis and 40 had renal insufficiency. Thus far, 36 patients (50 stenoses) have undergone a total of 52 follow-up angiographic studies. Clinical data, including blood pressure response, were obtained in all cases. Only 7 of the 98 hypertensive patients failed to respond to PTA. Of the 11 patients treated primarily for renal insufficiency, 5 improved. Of the 29 hypertensive patients who also had elevated BUN and creatinine, renal function improved in 13. Altogether, 96 patients (88%) benefited from the procedure. Analysis of long-term results suggests that PTA should be the treatment of choice for fibromuscular dysplasia and short, segmental atherosclerotic lesions and could also prove helpful in improving renal insufficiency.