To evaluate the efficacy of balloon-expandable (Palmaz) stents in the treatment of atheromatous renal artery stenosis, prospective placement of stents in 24 arteries in 20 patients was performed over an 18-month period, Indications were hypertension in 18 patients and renal insufficiency (serum creatinine > 1.5 mg/dL) in 11, and all lesions failed conventional transluminal angioplasty, Technical success was achieved in 96% of cases, Hypertension benefit was noted in 77% of patients followed for 6 months (n = 13) and 67% of patients at 1 year (n = 8), Improvement in serum creatinine was seen in 71% (n = 7) and 100% (n = 3) of azotemic patients evaluated at 6 and 12 months, respectively. Six-month angiographic patency was identified in 13 of 16 treated sites, Renal artery stent placement resulted in one asymptomatic segmental branch occlusion; there were no other procedural complications, In conclusion, renal artery stent placement is a technically and clinically effective treatment for hypertension and azotemia due to renal artery stenosis. (C) 1996 by the National Kidney Foundation, Inc.