Percutaneous transluminal angioplasty has attracted a great deal of attention in recent years and is being used with increasing frequency for the treatment of renovascular hypertension from renal artery stenosis. One hundred forty dilatation procedures have been performed in 90 patients with 119 renal artery stenoses. Ten of the patients were treated for renal insufficiency alone. An initial success rate of 95% was achieved. The blood pressure response has been followed for 1-52 months (mean, 22 months). The mean diastolic pressure decreased by 36.7 mm Hg in response to the treatment. Of the 80 hypertensive patients, 25 were classified as cured, 47 as improved, and eight as nonresponders. Patient selection, the proper balloon size, and a good initial response are the major factors in determining long-term success. Percutaneous transluminal angioplasty is technically feasible and clinically effective for the treatment of renovascular hypertension.