Fourteen patients, who had undergone surgery for rectal carcinoma, were studied by MR imaging to evaluate the presence of recurrences. MR results were compared to those obtained by needle biopsy or laparotomy. MR imaging proved to be a valuable method in diagnosing tumor recurrences on the basis of tissular morphology, whereas its capabilities were poor in differentiating recurrence from fibrosis on the basis of the signal intensity on T2-weighted images.