We report on 21 severely hypertensive patients with renal artery stenosis and renal insufficiency in whom percutaneous transluminal angioplasty and/or renal artery surgery was done in an effort to lower blood pressure and to preserve renal function. Of 12 patients who underwent angioplasty renal function and blood pressure improved in 3. Of the 9 patients without improvement 4 suffered permanent oliguric renal failure. An operation was performed in 12 patients, 4 after having failed angioplasty (1 was treated at another institution before referral for surgery). Two patients died postoperatively but 10 improved, with followup in 6 exceeding 3 years. This retrospective experience suggests that percutaneous transluminal angioplasty is not likely to supplant an operation in the treatment of patients with atherosclerotic renovascular hypertension and renal insufficiency.