Kidney cancer is not a single disease. It is made up of a number of different types of cancer that occur in the kidney, each with a different histologic type, having a different clinical course, responding differently to therapy and caused by a different gene. The identification of families with a predisposition to the development of renal neoplasms, including von Hippel-Lindau (VHL), hereditary papillary renal carcinoma (HPRC), Birt-Hogg-Dubé (BHD), and hereditary leiomyomatosis and renal cell cancer (HLRCC), has made possible the identification of the different genes for these cancers. The genetic basis for each of these has been identified with current investigation focusing on the mechanisms of carcinogenesis. The elucidation of molecular pathogenesis in these familial forms of kidney cancer should provide the opportunity to determine successful approaches for novel therapeutic agents.