A device for treating blood in an extracorporeal blood circuit, the device including a centrifugal pump provided with a transparent enclosure that is connected, by means of an inlet duct, to the outlet of a venous reservoir, the venous reservoir having an inlet that is connected to receive blood from a patient. The transparent enclosure of the pump is connected monolithically to the base of a structure that comprises a heat exchanger and an oxygenator. The structure also supports monolithically, at the peripheral region, an arterial filter that receives the blood in output from the oxygenator and is provided with a connector for coupling to an arterial line for return of the blood to the patient.
