Aortoesophageal fistula is a rare cause of massive gastrointestinal hemorrhage, and may occur as a sequela to prosthetic replacement of the thoracic aorta. Esophageal compression necrosis with leakage of microorganisms into the proximal suture line is probably central to pathogenesis. Like the more common aortoduodenal fistula, diagnosis by traditional radiographic and endoscopic methods is difficult. We report here such a fistula, in which computed tomographic soft tissue abnormalities were characteristic of perigraft abscess; fistulization occurred subsequently. CT holds potential for being a sensitive study to show localized perivascular infection, an important precursor to aortoenteric fistula, and as such should be positive early in the development of a fistula.