Patients with papillary and follicular thyroid carcinomas are said to have an excellent long-term prognosis. However, over 90% of papillary carcinomas have synchrone lymph node metastases. Based on clinical, histopathologic and molecular-biological factors, different patient groups can be defined with an increased recurrence rate and disease related mortality-rate of up to 50% in the long-term follow-up of 30 years. Therefore, not only the extent of the surgical resection of the thyroid cancer but also the lymph node dissection as an oncologic correct surgical procedure is of great importance. Although the position of surgical lymphadenectomy is still discussed controversially there are increasing reasons to support the concept of a radical initial operation following the rules of oncologic surgery. We consider total thyroidectomy and modified neck-dissection as the standard operation in well differentiated thyroid carcinoma. In unilateral carcinoma both the central and the ipsilateral cervico-lateral lymph node compartments are dissected. In multicentric bilateral carcinomas a bilateral cervico-central and cervico-lateral lymphadenectomy has to be performed.