Usual treatments combining surgery, radiation therapy, chemotherapy and hormonotherapy are poorly effective. The immunotherapy gave and objective response rate of 25% but is associated with many side effects. Multidrug resistance (MDR) can be explained, in part, by an mdr1 gene overexpression in renal carcinoma. The MDR is related to expression of a 170 Kda membrane glycoprotein, the so-called P glycoprotein (Pgp). This protein is able to extrude from cytoplasm drugs with various structures and mechanisms. Reversal compounds capable of inhibiting Pgp, given with antineoplastic drugs, could be able to increase their intracellular concentrations. Nevertheless, renal cell carcinomas are characterized by their multifactorial resistance and a better knowledge in this field will allow to design new circumvention resistance to chemotherapy.