A 66-year-old man with an abdominal aortic aneurysm and coexisting horseshoe kidney is reported. The aneurysm was successfully replaced by a prosthetic graft without resection of the renal isthmus. Because of renal blood supply and location of renal isthmus, aortic reconstruction presents a significant technical problem. Preservation of multiple renal arteries may be facilitated by preoperative aortography, and retraction of the renal isthmus offers good operative exposure.