[en] Surgery for abdominal aortic aneurysm may be challenging when rare renal or venous anomalies are present. This article reports two similar cases of aortic abdominal aneurysm associated with horseshoe kidney and left-sided inferior vena cava treated with a transperitoneal approach. Preoperative knowledge of the anatomic situation enabled appropriate aneurysm repair. Operative strategy is discussed. This report describes an uncommon venous vascular malformation complex and stresses the importance of computed tomography imaging not only in assessing the characteristics of the aneurysmal disease but also in detecting variations in pertinent vascular or parenchymal anatomy.