The overall prognosis of patients with differentiated thyroid cancer is excellent, but the prognosis is rapidly worsening, when the disease is diagnosed in elderly patients. Old patients more often present with poor prognostic features, such as large tumors, follicular or Hürthle cell subtypes, extrathyroidal growth and distant metastases. Therefore, an optimal therapeutic approach is recommended. Current therapy includes a total thyroidectomy, if necessary combined with a lymph node dissection and followed by high dose radioiodine ablation. Radioiodine therapy in elderly patients meets specific problems, concerning thyroid hormone withdrawal, side effects of 131I and nursing problems. Additional treatment of residual, recurrent or metastatic disease must be tailored, according to the stage of the disease, and should not be denied on the basis of chronological age. Lifelong treatment with suppressive thyroid hormone therapy does not lead to important long-term side effects at old age.