After reviewing this tutorial, the users should be able to list the most important characteristics of the ideal therapeutic radiopharmaceutical and briefly discuss each of these as it relates to current practice in Radionuclide Therapy. In addition, they should be familiar with the various thyroid diseases that are treatable with radioiodine and should know the activities administered for each condition and the radiation dose delivered to the patient. They should also be able to describe P-32 therapy for patients with polycythemia vera and malignant effusions, and should be able to identify the appropriate radiopharmaceutical for each of these diseases. They should be able to describe the procedure, radiation dosimetry, and projected outcome in patients treated with Sr-89; chloride for palliation of bone pain secondary to metastases; and should be able to describe the treatment of intractable rheumatoid arthritis using radiation synovectomy with radiolabeled ferric hydroxide macroaggregates.