A rare case of diffuse ganglioneuromatosis with plexiform neurofibromas limited to the gastrointestinal tract in a 20-year-old man is reported. The patient had no cafe-au-lait spots or any apparent tumorous lesions affecting other organs. A fan-shaped resection of the mesentery, including 200cm of the ileum, together with ileocecal resection was done, and the diagnosis was histologically confirmed. The relationship between this benign tumor and other neurogenic disorders is discussed, along with a review of the literature. Long-term follow up of this patient is required because of the possible development of von Recklinghausen's disease or multiple endocrine neoplasia type IIb.