This is a case of a 54-year-old male, diagnosed to have insular thyroid carcinoma. The histopathologic characteristic of this rare neoplasm arising from follicular epithelial cells has the potential to take up 1-131 As shown in his postoperative 1-131 imaging, there are iodine-avid lesions in the parietal bone, thyroidal beds, ribs and vertebrae. The presence of these lesions in a &agnostic radioactive iodine scan makes it possible to do radioactive iodine therapy. A follow-up diagnostic study with 1-131 shows interval resolution and regression of the metastatic lesions. Thus, radioactive iodine therapy has a role in the treatment of this rare and aggressive neoplasm.