The indication for elective organ-preserving surgery in renal cell carcinoma is under discussion. The statements about the maximum tumor size, which could be considered for this surgical procedure, differ in the literature. In a series of 281 consecutive radical tumor nephrectomies we compared the results of preoperative ultrasound and computerized tomography regarding to tumor size and multifocality with the results of the postoperative systematically section of the removed kidneys. Further we analysed the results of 14.793 autopsies regarding to tumor size and multifocality. Serial section of the 281 nephrectomy specimens revealed a total of 64 multifocal tumors in 48 kidneys ( = 17,1 %). The correlation between tumor size and multifocality showed only in tumors up to 20 mm no additional lesions, whereas in the higher tumor categories the incidence was up to 23 %. These clinical investigations were confirmed by the results of the autopsies. In summery of the results we conclude, that the elective organ-preserving surgery of renal cell carcinoma is only indicated in tumors with a maximum diameter of 20 mm.