For surgery to cure renovascular hypertension, one must make certain that a renal artery stenosis is causative and not coincidental. Patient selection, using the renal vein renin assay and, when necessary, divided renal function tests, is therefore the key to a successful outcome. It is held that the optimal procedure, which is demonstrated in an“ideal”candidate, is bypass of the stenosis by means of an autologous saphenous vein graft.