patients underwent operations for renovascular hypertension between September, 1971, and August, 1979. In 75 (37.2%) of the patients (64 female and 11 male, ages 8-55 years), a fibrodysplastic stenosis of one or both renal arteries was found. These patients were treated after angiographic demonstration of a renal artery stenosis, with no further functional testing, e.g., renal vein renin ratio or Saralasin test. Operative procedures included resection of the stenosis and reanastomosis in 45, vein patch angioplasty in 13, vein graft reconstruction in 11, and reimplantation of the renal artery into the aorta in 6 patients. In 5 patients (6.7%) a nephrectomy was necessary because of artery thrombosis. There were no operative deaths. Ninety-six percent of the patients showed a normal or improved blood pressure in the immediate postoperative course. In more than 85% of the patients, reinvestigated 2, 4, and 6 years after the operation, hypertension was cured or improved. We conclude that surgical treatment of renal artery stenosis of fibrodysplastic origin is indicated without further functional tests.