Summary: Thyroid cancer ranges from well- differentiate lesions with excellent prognosis to anaplastic carcinoma which is almost uniformly fatal. Thus, methods to assess the behavior of thyroid malignancis are necessary to arrive at appropriate treatment decisions. We discus the factors (TNM staging system; Staging of the disease; AGES,AMES and MACIS scoring system) that affect the prognosis of patients with thyroid cancer.