The possibility of multiple use of Cuprophan capillary dialyzers reutilized with our own method with a help of an automatic apparatus produced according to our own constructive assumptions was evaluated. The experiments were carried out using capillary dialyzers of the Organon Technika firm, Andante H.F. type with 8 mu thickness of a Cuprophan capillary++ membrane and a dysfusion surface of 0.8 m2. Complete sterility of the regeneration process and full wash of the disinfectant (formaldehyde extract) were observed before reusing of the dialyzer. The clearance of creatinine did not lower when the regenerated dialyzers were used. During the first use of the dialyzer it was 105.8 +/- 8.9 ml/min, and during the sixth one--105.5 +/- 9.8 ml/min. In a group of 24 patients first dialyzed using dialyzers only once and then after 4 months' dialyzing with dialyzers used at least 6 times and again after 4 months' of further dialyzing using a dialyzer only once, remarkable changes of the concentration of urea, creatinine, hydrogen carbonates, fibrinogen, the hematocrit indicator, the amount of hemoglobulin, the number of hematocytes, blood platelets and the weights of the patients in blood serum were not observed. Differences in the before-mentioned indicators between the group of patients dialyzed with a multiple used dialyzer and group of 7 persons dialyzed at the same time with a dialyzer used only once were not observed. During 1075 dialyses made using reutilized dialyzers negative phenomena which might be connected with multiple use of dialyzers were not observed in patients. The authors come to the conclusion that the automatic reutilization of their own method does not lower the efficiency of hemodialysis, lowers the risk of the first use syndrome and is well tolerated by patients which with simultaneous lowering the costs of dialysis as is much for multiple use of dialyzers.