In recent years preoperative transcatheter embolization has been used widely in the management of kidney tumors. However, the effective clinical usefulness of this method has not yet been proved. Forty cases of kidney tumors treated by preoperative embolization and radical nephrectomy are reviewed and compared with a homogeneous group of patients who did not undergo preoperative embolization. Intraoperative blood loss, postoperative complication, and survival rate were statistically evaluated according to tumor stage. Advantages and disadvantages of preoperative transcatheter embolization of kidney tumors are reviewed.