Aortocaval fistulas most frequently occur as a consequence of ruptured abdominal aortic aneurysms due to the additional trauma, spontaneous or iatrogenic. The basic symptomatology is the consequence of local irritation of spinal nerves, and major hemodynamic disturbances. In this paper we have presented two cases of aortocaval fistulas, treated at the Military Medical Academy with presentation of their preoperative status, performed diagnostic procedures, applied surgical procedures, and postoperative course and outcome.