From 1974 to 1989, 18 patients underwent surgical treatment for isolated dissection of the renal artery causing high grade stenosis, including 2 patients with bilateral renal involvement. The causes of renal artery dissection were blunt trauma (1 patient), unsuccessful percutaneous transluminal angioplasty (5) and atherosclerosis (5) or intimal fibroplasia (7) of the renal artery. The most common presenting signs or symptoms of a dissection were hypertension (94%), an abdominal bruit (44%), headache (44%), minimal proteinuria (44%), microscopic hematuria (38%) and flank pain (38%). Renal artery dissection led to segmental or total renal infarction in 8 of 20 involved kidneys (40%). Seventeen patients underwent unilateral surgical revascularization with amelioration of hypertension and preservation of renal function. Three kidneys were lost due to irreversible ischemic damage from an occlusive dissection. Isolated renal artery dissection is an uncommon lesion that can cause hypertension and threaten renal function.