Critical examination of the results of surgical treatment and new surgical techniques have produced changes in the operative treatment of hypernephroid kidney cancer and nephroblastoma. The limits to operative treatment are, first, the local extension and infiltration of the tumor and, second, the grade and degree of metastases. Surgical removal of the hypernephroma seems to have a positive effect on metastasis regression only in the case of bone metastases. Nephrectomy is indicated only in cases with solitary metastases which can be removed at a second operation. The possibility of arterial embolization in renal hemorrhage in inoperable patients is demonstrated. Current aspects of the operative treatment of nephroblastoma are discussed.