Multiple large bowel polyps are the hallmark of familial adenomatous polyposis (FAP), and many progress to colorectal cancer. Desmoid tumors are more common in patients with FAP than in other people, occurring, particularly, in those who have previously undergone prophylatic total colectomy. In such patients, desmoid tumors are a common cause of death. In an FAP patient without extracolic manifestation, who has undergone prophylatic surgery, multifocal desmoid tumors occur periodically. We report the serial radiologic findings of progressive desmoid tumors in FAP, drawing attention to the related findings of previous research.