We present a case of 71 year old man operated in our clinic for ruptured abdominal aneurysm complicated with aorto-caval fistula, which was revealed during the surgery and successfully repaired by direct sutures within the aorta. This is the first record of the aorto-caval fistula that was so far noticed in our clinic. Urgent surgery and repair of the defect conneting aorta and vena cava by direct sutures within the aorta followed by ruptured aneurysm repair with tube graft is only way of treatment. Despite its infrequent occurrence, aorto-caval fistula should always be considered in any case of ruptured abdominal aneurysm.