Recently, there has been a significant increase in the knowledge about the molecular basis of renal cell carcinoma. Its sporadic form is characterized by a deletion on the short arm of chromosome 3, even for localized stages. The same genetic abnormality is found in renal cell carcinomas associated with the von Hippel-Lindau disease. Such findings strongly suggest the presence of a common tumor suppressor gene which seems involved in the genesis of sporadic renal cell carcinoma and in the predisposition of hereditary cancers. Other tumor suppressor genes located on other chromosomes, as well as over expression of growth factors, seem to be related to the progression of this malignancy. Further studies of the molecular events associated with cellular transformation should help to better understand the behavior of such cancers and to find new therapeutical approaches.