Purpose: To describe midterm outcome of endovascular stent-graft repair of a mycotic aneurysm associated with a peripancreatic allograft abscess after transplantation. Case Report: A 46-year-old woman underwent combined kidney and pancreas allograft transplantation under heavy immunosuppression. She developed a peripancreatic allograft abscess with associated mycotic aneurysm of the pancreatic allograft donor iliac artery 2 months after transplantation. Endovascular stent-grafts were used to exclude the aneurysm, retaining normal pancreatic allograft function over the next 2 years. Conclusion: Allograft arterial mycotic aneurysm development after transplantation is a rare but potentially life-threatening problem. This case suggests that control of a mycotic aneurysm may be obtained with stent-grafting in the presence of active infection under intense immunosuppression, avoiding allograft pancreatectomy. J Endovasc Ther. 2011; 18: 607-610