Identification of numerical abberations of chromosome #3, #7, #11, #17, #18, X and Y were evaluated using biotinylated probes specific for the alpha satellite region on paraffin embedded sections from formalin-fixed materials of renal cell carcinoma utilizing in situ hybridization (ISH). The copy number of each chromosome did not show any correlation with tumor grade, clinical (Robson) stage, pT, pN, pV or the presence of metastasis. Copy numbers of #3 chromosome were highly correlated with the patient prognosis (p < 0.01). Since numerical abberations of #3 chromosome are suggested to be correlated with the prognosis of renal cell carcinoma, this technique can now be applied to the detection of biological activity in renal cell carcinoma.