We report here the sixth known case of metastatic renal tumor of thyroid carcinoma. In 1999, a 37-year-old man was referred to us with a left renal mass found incidentally by ultrasound during an annual check-up. Computed tomography (CT) revealed a well-defined, hyperdense mass 3 cm in diameter in the middle of the left kidney. Left radical nephrectomy was performed under the preoperative diagnosis of renal cell carcinoma. Histologically, the tumor was metastatic of typical papillary thyroid carcinoma.