A rare case, presented as a secondary aortoenteric fistula after an abdominal aortic aneurysmectomy with Y-graft replacement 9 months earlier, is reported. The course was clinically very unique, in that the first manifestation of the aorto enteric fistula occurred while the patient had already been hospitalized after the orthopaedic surgical treatment for the pyogenic vertebral spondylitis. After the episode of gastrointestinal bleeding, radiological studies were promptly collected, and with the proper diagnosis, a successful surgical treatment was given under the stable hemodynamic condition, and the patient recovered uneventfully. Retrospectively considered, there are several findings that would suggest that seemingly a secondary aorto enteric fistula could have resulted from an early process of the primary aorto enteric fistula having been under progress without any detectable manifestations before the previous aneurysmectomy. The diagnostic values of computed tomography and the scintigraphy for this rare clinical entity is also underlined.