This report describes the treatment of bilateral common iliac artery aneurysms in a patient with a pelvic horseshoe kidney. Anomalous renal arteries arising from the aorta, the common iliac arteries, and the left hypogastric artery were identified precisely by selective angiography. These multiple renal artery anomalies and the presence of a large pelvic horseshoe kidney complicated the surgical treatment of the aneurysms. The repair of the aneurysms was successfully accomplished by staged retroperitoneal procedures. This technique allowed excellent visualization of the iliac aneurysms and preservation of all renal arteries with intact renal function.