Method for at least partial emptying of an extracorporeal blood circuit after the blood of a patient in the extracorporeal blood circuit has been re-entered into the patient with the help of an infusion fluid that displaces the blood and that the patient was separated from the extracorporeal blood circuit, where the extracorporeal blood circuit has a conduit for arterial blood (5) that is conducted from an arterial connection point (13, 14) to the blood chamber (3) of a hemodialyzer (1) divided by a semipermeable membrane (2) in a blood chamber (3) and a dialysis fluid chamber (4), the blood chamber (3) of the hemodialyzer (1), as well as a conduit for venous blood (7) that are conducted from the blood chamber (3) to a venous connection point (15, 16), where without additionally connecting with each other the venous blood duct and the arterial blood duct, the arterial blood duct ial (5) is actively or passively ventilated at a first point (50) and the venous connection duct (7) is vented at a second point (40), and the liquid in the blood chamber (3) of the hemodialyzer (1), as well as in the section of the arterial blood duct (5) between the blood chamber (3) and the first point (50) and in the venous blood duct section (7) between the blood chamber ( 3) and the second point (40) is emptied in the dialysis fluid chamber (4) and in a dialysis fluid discharge conduit (21) leaving said chamber, by means of the semipermeable membrane (2).Método para el vaciado al menos parcial de un circuito de sangre extracorporal después de que la sangre de un paciente que se encuentre en el circuito de sangre extracorporal haya sido reingresada al paciente con la ayuda de un líquido de infusión que desplaza la sangre y de que el paciente fuera separado del circuito de sangre extracorporal, donde el circuito de sangre extracorporal presenta un conducto para sangre arterial (5) que se conduce desde un punto de conexión arterial (13, 14) hacia la cámara de sangre (3) de un hemodializad
