CT scans were performed 40 times in 28 postcystectomy patients to identify the type and location of tumor recurrence. Sixteen patients showed tumor recurrence. Patients without recurrence showed a complete symmetric pelvis and a thin string that looked like an operation scar. Cutaneous ureterostomy showed small tube-like structures, and ileal conduit looked like herniation of the ileum. Cases with recurrent tumors were divided into 3 patterns, 1) pelvic abscess recurrence, 2) anterior abdominal wall thickening, 3) pelvic lateral wall thickening, and combinations of these types. The abscess-recurrence type often showed air within the mass or a fuzzy contour that could not be differentiated from true inflammatory abscess. Anterior abdominal wall thickening was usually accompanied with abscess-type recurrence and appeared as thickening of the operation scar. Lateral wall thickening was usually seen at the site of the obturator internus muscle or obturator node. Patients without recurrence had no complaints except for two who had ileus. All patients with recurrence except one had complaints of pain, abnormal secretion, or a palpable mass. Because all patients with recurrence already had a relatively large tumor at the time of CT, routine follow-up CT is recommended even if the patient has no complaints.