Patients diagnosed as suffering from highly malignant thyroid tumours die within a few months due to rapid tumour progression. Survival depends on some valuable prognostic factors, namely tumour size, lymph node involvement, metastatic status, fast tumour growth and preoperative N. recurrens paresis. Life expectation and life quality are dependent on the feasibility of radical surgical treatment. It is necessary to remove the whole tumour to improve the survival rate and to reduce the incidence of local recurrence. Some highly malignant thyroid tumours show a high chemosensitivity.