The renovascular hypertension is a rare disease in which obstructive lesion of renal artery results in hypertension and it is the most common surgically curable form of hypertension. Recently, we experienced two cases of renovascular hypertension treated successfully with resection of the stenotic segment and end-to-side reanastomosis of the renal artery to the aorta in one case, and with resection of the stenotic segment and saphenous vein bypass graft in the other case at the Thoracic & Cardiovascular Surgery, Chungnam National University Hospital. Pathologic examinations revealed fibromuscular dysplasia of the medial layer of the renal artery in both cases