Secondary aortoenteric fistula (SAF) is a rare but fatal complication of reconstructive aortoiliac surgery. The prevention, diagnosis and treatment of this complication remains a challenging problem in everyday practice. Nine cases of secondary aortoduodenal fistulae during the period of 1980 to 1992 are presented. Their main symptom was bleeding of the upper gastrointestinal tract. The mean time interval since the aortic surgical procedure was 32 months. Removal of the old graft and closure of the duodenal defect was the first stage of the operative procedure. One patient underwent replacement of the old graft, with a new graft, while in the remaining three patients extranatomical bypass was not necessary because of satisfactory circulation in the lower extremities. In five patients extranatomical revascularization of the lower limbs was performed postoperatively at various intervals. Three patients died postoperatively. Follow-up of the remaining patients ranged from one month to 8 years. Bleeding of the upper gastrointestinal tract in patients with a history of intrabdominal reconstructive vascular surgery must raise severe suspicion as to the certainty of existance of SAF unless the diagnostic procedure, mainly exploratory laparotomy, excludes this possibility.