In the last years the incidence of renal cell carcinoma diagnosis increased about 15-20%. The main aim of this study was to analyse the reason of the increase of incidence. In the present autopsy series comprising 23,801 autopsies the percentage of patients who died of renal cell carcinoma is 1.77% in Jena and 1.55% in Königgrätz (200,000 inhabitants each). Over this time the incidence of renal cell carcinoma in autopsies has increased. In spite of the increased amount of incidentally found renal cell carcinomas since beginning widespread use of ultrasonography the percentage of clinically recognized renal cell carcinomas on the total of all found renal cell carcinomas in autopsies is nearly constant about the 12-year period in Jena and 10-year period in Königgrätz. Thus, the increased number of radical nephrectomies is not only caused by widespread use of ultrasonography. The increasing trend of the incidence of renal cell carcinoma seems to be real.