Abstract: In a closed system for collecting and retransfusing autologous blood having a collecting vessel (4) to receive the blood and an anticoagulant fluid, as well as a retransfusion line (14, 14') containing a microfilter, through which at least a portion of the blood collected in the collecting vessel (4) is retransfused, the inlet for the anticoagulant fluid is provided, preferably between the collecting vessel (4) in which a negative pressure can be maintained and a drain (2) or the open end of a drain tube. The collecting vessel (4) is connected with a collecting and separating container (13, 13') by means of a tube line (10, 10'), to which a tube pump (11) can be applied. The retransfusion line (14, 14') for the erythrocyte concentrate deposited in the collecting and separating container (13, 13') is connected to the outlet thereof.