A primary aortocaval fistula is present in less than 1% of all abdominal aortic aneurysms. Until recently, surgical repair was the only method of treatment and was associated with a high incidence of morbidity and mortality. With the rapid development of aortic stent-graft technique, endovascular stent-graft repair may offer an alternative to the management of this often fatal condition. We report a case of an aortoiliac aneurysm with an aortocaval fistula successfully treated with endovascular stent-grafting. The unique hemodynamic changes, technical problems, and complications associated with this case are discussed, and the literature is reviewed. (J Vasc Surg 2001;33:425-8.)