The authors report three siblings (two sisters and their aunt, aged 20, 22 and 36, respectively) with familial adenomatous polyposis (FAP) and papillary thyroid carcinoma. After diagnosis of FAP, a single, non palpable nodule was revealed in each patient by routine screening ultrasonography of the gland, The diagnosis of papillary carcinoma was made by fine-needle-aspiration biopsy of the nodules and confirmed by histologic examination of surgical specimens. A review of the literature reveals about 40 reports of such an association, that is considered not fortuitous. Nevertheless, in this family the association seems to be a distinctive, clinical feature of the syndrome, affecting three out of five members intensively screened for extracolonic lesions.