Primary renal sarcomas of the kidney in adults are unusual, accounting for approximately 1% to 3% of all primary renal malignancies. Pathologically, leiomyosarcomas are the most frequent tumors of primary renal sarcomas, and fibrosarcomas of the kidney are rare. We report on a 46-yr-old male admitted to our hospital due to right side renal tumor. He received radical nephrectomy, and the histopathological report revealed primary fibrosarcoma of the right kidney. He received adjuvant radiotherapy with 5000 cGy due to invasion of the retroperitoneal muscle. Multiple organs metastases of lung, liver and bone developed 2 mo after nephrectomy. He died of the disease 6 mo after surgery. Prognoses of fibrosarcomas. Chemotherapy or radiotherapy is not helpful for survival. Herein, we present this case and review the literature.