Gardner's syndrome is a congenital condition characterised by diffuse intestinal adenomatous polyposis (IAP) associated with maxillary osteomas, odontomas, hypertrophy of the retinal epithelium and skin tumours. It may affect subjects of all ages with equal frequency in males and females. The fact that diffuse adenomatous polyposis, the most serious clinical aspect of the syndrome, is treated surgically, has led to improved survival in patients and, consequently, an increased incidence in associated lesions, particularly maxillary osteomas. A personal case observed at the Odontostoma-tological Clinic of the University of Rome La Sapienza is reported.