Familial adenomatous polyposis (FAP) includes early development of up to thousands of colorectal adenoma and of colonic adenocarcinoma in all untreated cases. Moreover, a variety of extracolonic manifestation are seen. Several reports have demontrated a high incidence of papillry carcinoma of thyroid. We experienced a case of familial adenomatous polyposis, presenting with thyoid papillry carcinoma, and reported with a brief review of literatures.