[en] Current treatment of well-differentiated thyroid cancers (DTC) includes total or near-total Thyroidectomy and postoperative ablation of the thyroid remnant by radioiodine (I-131) in most patients. After initial therapy the life-long hormonal therapy is necessary. The incidence of palpable neck metastases (N1) is 15 to 40% in papillary thyroid carcinoma (PTC) and less than 20% in follicular thyroid carcinoma (FTC). Surgery is the most important treatment for regional disease. Therefore, modified regional neck dissection should be performed in cases of regional lymph node metastases. Radioiodine treatment should be repeated by administered radioactivity ranging from 5.55 GBq to 7.4 GBq with 3 to 6 month intervals between doses. There is no maximum limit to the cumulative dose of radioactivity that can be administered to patients with persistent disease, provided that individual doses do not exceed 2 Gy for total body exposure. Distant metastases (M1) outside of the neck develop in up to 10% of DTC patients. Half of the distant metastases are present initially. Distant metastases at presentation predict a poor prognosis. Papillary carcinomas are most likely to spread via lymph nodes to the lungs. Follicular carcinomas produce metastases through haematogenous spread. Pulmonary metastases are more often detected in PTC patients and in young patients, while bone metastases are more frequently found in FTC patients. Organs most commonly affected by distant metastases are the lungs and bones, with the liver and brain being rarely involved. Treatment for distant metastases should include radioiodine therapy, external beam radiotherapy and surgery in large and/or non-iodine avid tumours. In non-iodine avid tumours further radioiodine therapy should be avoided. The thyroxine hormonal therapy is performed as a post-operative and post-radioiodine life-long treatment. External beam radiotherapy is applicable occasionally, if postsurgical tests of primary tumour and/or metastatic foci do not accumulate radioiodine and can not be completely surgically removed. Optional treatment includes chemotherapy which has limited success. Time tested protocols over several decades have shown that appropriate and timely treatments which include adequate surgery and I-131 therapy are necessary for better prognosis and outcome of DTC patients. Metastatic differentiated thyroid carcinoma should be treated at first place by surgery and radioiodine treatment. Optional therapeutic strategy includes external beam radiation therapy and chemotherapy which can be performed in non-iodine avid metastases. (author)