We examined the effect of left renal vein (LRV) division during abdominal aortic aneurysm operations on renal function during the recovery period. Fifteen patients with LRV division were compared with 26 patients in whom the LRV was not ligated. These two groups of patients did not differ significantly in any of their preoperative characteristics, operative management, or postoperative complications. Preoperative, highest postoperative, and predischarge levels of plasma urea and creatinine, as well as urinary sediment, were compared in both groups. Left renal vein division could not be implicated as a cause of renal function deterioration and was found to be a safe, useful adjunct to abdominal aortic aneurysm surgery.