A 69-year-old woman was evaluated for anemia. Abdominal ultrasonography showed a large right renal mass. Magnetic resonance imaging revealed a 12-cm renal mass and a separate 7.5-cm ipsilateral adrenal mass, with a tumor thrombus extending through the adrenal vein and into the inferior vena cava. Right radical nephrectomy/adrenalectomy with caval tumor thrombectomy was performed, and both lesions were diagnosed as renal cell carcinoma. We report on an unusual case of a large renal cell carcinoma with metastasis to the adrenal gland and vena caval extension by way of the adrenal venous system, without renal vein thrombus.