A cardiotomy reservoir (1), comprising an outer wall (2) provided, at the lid (2a), with connectors (3) for the inflow of blood to be filtered and, at the bottom (2b), with a connector (4) for the outflow of the filtered blood, a filtering mass (6) being provided which divides the space delimited by the outer wall (2) into a portion (5) that is connected to the inflow connectors (3) and a portion (7) that is connected to the outflow connector (4) the cardiotomy reservoir comprises a layer (6b) of material adapted to retain fats present in blood, and further comprises a first partition (11) and a second partition (10), which are adapted to delimit at different distances the region that comprises the blood outflow connector (4) and are provided with ports (10a,11a) for the passage of the blood in its path for accessing the connector which are arranged at differentiated levels with respect to the bottom, the ports (11a) that are provided in the first partition that lies closest to the outflow connector being located at a height, from the bottom (2b), that is greater than the height of the ports (10a) provided in the second partition (10), detachable means for blocking the blood outflow connector (4) being further provided.
