Gardner syndrome (GS) is an abnormality of familial adenomatous polyposis accompanied by characteristic jaw lesions. Gardner syndrome intestinal polyps have a 100% risk of undergoing malignant transformation; consequently, early identification and surgical intervention of the disease are important to prolong the life of the patient. We present a case of GS in a 55-year-old woman. Familial adenomatous polyposis, osteomatous jaw and ocular lesions, several dental abnormalities, and an abdominal desmoid tumor are the characteristic features of this case. This case demonstrates the presence of unusual, widespread, hereditary, osteomatous jaw lesions that caused diagnostic confusion with familial gigantiform cementoma.