We present a 75-year-old-man affected by chronic renal failure in whom metastases from differentiated thyroid cancer (DTC) were incidentally discovered at TcO4 neck-thorax scan in the setting of a diagnosis of secondary hyperparathyroidism. Ten years before, he had undergone near-total thyroidectomy for a multinodular goiter. Result of the pathological examination was negative for DTC. At our observation, serum thyroglobulin was high in the absence of Tg-Ab, consistent with metastatic disease. Neck ultrasonographynography was negative. The patient underwent I therapy (3700 MBq) after stimulation with recombinant human thyroid-stimulating hormone. Postdose whole-body scan confirmed the metastases already demonstrated by TcO4.