Genitourinary anomalies can present a formidable challenge to the vascular surgeon at abdominal aortic reconstruction. We saw a case of crossed renal ectopia without fusion, a rare anomaly, associated with abdominal aortic aneurysm. Because of risk for injury to the kidney during surgery, preoperative evaluation of this anomaly must include computed tomography, angiography, and intravenous pyelography. Preoperative placement of a ureteral catheter may prevent injury to the anomalous ureter. Renal failure of the ectopic kidney during aortic reconstruction can be a serious problem. We used in situ hypothermic perfusion with cold (4 degrees C) Ringer solution for renal protection, and reimplanted the aberrant renal artery. The postoperative course was good, without major complications. The procedure for renal preservation must be selected on the basis of anatomic findings. We review the literature and present the first case of crossed renal ectopia.