The surgical repair of 16 aorto-caval (A-C) fistulas (15 male and one female patient; average age of 61.3 years) is reviewed. Fourteen fistulas were caused by aneurysm's erosion, one by iatrogenic injury, while one followed abdominal blunt trauma. The interval from presumed occurrence to diagnosis ranged from 6 h to 2 years. The presence of an abdominal bruit (87.5%) was the most reliable physical finding. Congestive heart failure was prominent in three (18.7%) cases, while severe lower extremity edema in five (31.2%). Two patients (12.5%) had hematuria, two (12.5%) renal insufficiency, while four (25%) scrotal edema. The diagnosis was not recognized before the surgery in five (31.2%) cases. In all 16 cases after transaortic suture of the fistula, aortic reconstructions were performed. Four operative deaths (25%) occurred, in patients who were not correctly diagnosed before surgery. In one case the cause of death was massive bleeding, and in three MOFS. All other patients were followed from 1 to 17 years (mean 4 years and 2 months). All grafts are patent, and there is no lower extremity venous insufficiency or pelvic venous hypertension. Surgical repair of A-C fistulas is mandatory to prevent serious complications.