Fourteen patients with severe hypertension and renal artery stenosis were treated surgically. One patient died 4 days after surgery due to a cerebral thrombosis. The other 13 patients were followed for 18–24 months. Five were considered cured since the diastolic blood pressure (DBP) was ≤ 90 mm Hg without therapy. Five were improved since DBP was ≤ 100 mm Hg during treatment with only one or two antihypertensive agents. There were unchanged. Renal vein renin ratio (RVRR) was ≥ 1.5 either before or after furosemide in all patients who were cured or improved and ≤ 1.5 in 2 of 3 who were unchanged. It can be concluded that surgical treatment cured or improved 77% of the patients, and that a RVRR ≥ 1.5 is a good predictor of the blood pressure lowering effect of surgery.