The authors report a case of isolated mesenteric fibromatosis un associated with familial adenomatous polyposis or Gardner's syndrome or prior abdominal surgery. These neoplasms are usually asymptomatic until when the compression of the small or large bowel or the ureter causes symptoms; although they are benign lesions without metastases, local recurrences are very frequent. Surgical removal is the primary treatment; until now no satisfactory results have been obtained with other therapeutic modalities.