Patients with chronic kidney failure suffer from severe disorders of T and B lymphocyte function. Existing data confirm the absence of intrinsic defects of T and B cells, and shows major influence of urea and uremic toxins in the development of cellular immunodeficiency. In dialysis patients was determined predominance of T- suppressor lymphocytes (25.4% in study group) and 23.8% in the control group and values below the normal for total and active T lymphocytes (46.1% and 14.92 % in the study group, 46.8% and 14.9% in the control group, respectively). Hemodiafiltration led to a statistically significant decrease (p = 0.03) of T-suppressor lymphocytes - 18.7%, increase in T helper lymphocytes up to 41.6% (p = 0.003), and the total number of T lymphocytes, which increased from 46.1% to 60.0% (p = 0.004), number of active T cells increased from 14.92% to 21.2% (p = 0.02), T-morules - from 15.6% to 24.3% (p = 0.03)