Primary aorto-appendiceal fistula has been reported only once previously. A further case is presented in which bleeding, per rectum, occurred in association with rupture of an aorto-iliac aneurysm adherent to an acutely inflamed appendix. Postoperatively the patient had several complications including permanent asymmetrical L1 paraplegia and delayed presentation of an intramedullary abscess of the femur which grew Bacteroides fragilis organisms. These complications highlight the high morbidity associated with aortocolic fistulae.