The authors on the base of two cases of Gardner's syndrome recently observed, proceed to a wide review of literature on this subject so as to stress the peculiar aspects of this syndrome, so complex and uncommon. The greatest emphasis is given to the role of genetics as regarding to diagnosis and screening programs, as well as to the more recent acquisitions about diagnosis, therapy and follow up of risk lesions, such as colorectal and duodenal adenomas, as well as of intrabdominal desmoid tumours, which, although not histologically malignant, may often influence prognosis negatively, because of their remarkable local invasiveness and tendency to recurrence.