Immunological examination and endolymphatic treatment were performed in 44 patients with cancer of the kidney or urinary bladder. In the majority of patients lymphocytes of the peripheral blood demonstrated reduced expression of some differential antigens. Subpopulation of T-lymphocytes, expression of T-lymphocyte receptors got decreased in almost all the patients. Endolymphatic introduction of immunocorrective thymalin improved the patients' life quality, their immune status. However, the level and proportional expression of differential lymphocyte antigens following course polychemotherapy and immunocorrection in patients do not coincide with relevant parameters of healthy subjects. It is evident that further search for optimal treatment schemes is needed.