Patients with chronic renal failure (CRF) present an immunodeficient state manifested by an abnormally high incidence of malignant tumors, enhanced susceptibility to certain infections diseases, poor responses to influenza and hepatitis B vaccines. This state coexists paradoxically with activation of most immunocompetent cells, mostly monocytes and lymphocytes. A complexed net of reciprocally acting reasons of immunological processes in patients with CRF remains still unclear. Immunological response is bounded with release and functioning of cytokines. Plasma levels of many cytokines in patients with CRF are higher than in healthy control. The main role in this process plays the state of activation of monocytes provoked by the circulating endotoxins, which has been confirmed in those patients. Moreover, chronic renal failure itself and reactive oxygen species can cause a disregulation of production and elimination of these cytokines. The decreased clearance of cytokines due to renal failure can cause an accumulation of those proteins in blood. The origin, physiological role and disordered production of cytokines needs still further investigations in order to get a better understanding of a nature of dysfunction immune system in CRF patients.