During the last two decades, the incidence of thyroid cancer has doubled, mainly do to the early detection of small papillary tumors. However, mortality stayed stable (0.05/100.000). Well differentiated cancers (papillary and follicular) demonstrated a excellent survival prognosis (95 % at 30 years for the majority of the patients), factors of prognosis: age, size of the initial tumor, presence (or not) of distant metastases, lymph node involvement (only in patients 45 year or older). Surgery is the main treatment and should be with curative intent, hence the importance of a thorough preoperative work-up: sonography, needle aspiration cytology and MRI of cervicomediastinum for large tumors and/or suspected lymph nodes. Total thyroidectomy is mandatory, excepted for well selected patients with small (pT1) unilateral tumors under the age of 45. Central compartment lymph node clearance is advocated (but not evidence based) with presentation of the recurrent laryngeal nerves and of the parathyroids. Ablation of residual thyroid tissue (Iode 131) should be advocated for patients at high (or intermediary) risk of recurrence, only after multidisciplinary concertation. Unlimited follow-up checking the thyroglobulin serum local after the total thyroidectomy and radioactive ablation, the availability of recombinant rhTSH avoids the withdrawal of thyroid hormones (hypothyroid period). Anaplastic carcinomas are very aggressive, no therapeutic solution, excepted in some selected case for when radical surgery is possible (flap reconstruction) followed by chemoradiation. Calcitoninenia to detect and to follow medullary thyroid cancer after total thyroidectomy and lymph node clearance.