Recombinant human erythropoietin was injected intraperitoneally in a total dose of 900 U/kg to rats with experimental chronic renal failure. Suspension of lymphocytes from animals with chronic renal failure was used in vitro, erythropoietin was used in concentrations of 30, 15, 7.5, 3.75, and 1.88 U/liter. Intact cells (Annexin-5-FITC(-)/7-AAD(-)), cells with early signs of apoptosis (Annexin-5-FITC(+)/7-AAD(-)), cells with late signs of apoptosis and partially necrotic cells (Annexin-5-FITC(+)/7-AAD(+)), as well as cells with early signs of necrosis (Annexin-5-FITC(-)/7-AAD(+)) were differentiated by fl ow cytometry. It was found that the number of peripheral blood lymphocytes with early and late signs of apoptosis and necrosis increased in chronic renal failure. Erythropoietin at a total dose of 900 U/kg reduced the number of blood lymphocytes with signs of apoptosis and necrosis and thus elevated the number of intact lymphocytes. Erythropoietin in concentrations ranging from 1.88 to 30.0 U/liter dose dependently lowered the number of lymphocytes with early signs of apoptosis and the number of lymphocytes with the signs of late apoptosis and necrosis in vitro.