Cardiopulmonary bypass with deep hypothermic circulatory arrest has been established as a useful method in the surgical management of patients with rend cell carcinoma and large infe-rior vena caval tumor thrombi. We present our experience with 2 cases of renal cell carcinoma extending into the supradiaphragmatic inferior vena cave using cardiopulmonary bypass with deep hypothermic circulatory arrest. (j Urol R.O.C., 10:173-176,1999)