The occurrence of an aortocaval fistula (ACF) secondary to an abdominal aortic aneurysm (AAA) is uncommon and is often undiagnosed prior to AAA repair. Clinical signs may be subtle or absent; therefore, diagnosis requires a high suspicion and knowledge of this phenomenon. We present a case of the rarest form of ACF (type 4) in which an AAA and an occult ACF were associated with a second site of retroperitoneal rupture. The ruptured AAA and ACF were successfully managed with fistula ligation and aortic graft placement.