Abstract: An autotransfuser device for removing blood from a patient and returning the blood to the patient includes a collection bag suspended in an air jacket. A valve is provided in the device to selectively apply a negative pressure to the air jacket and the interior of the collection bag to draw the blood from the patient. The valve is subsequently rotated to apply a positive pressure to the air jacket and the outside of the bag to compress the bag and cause the blood to be returned to the patient. A plurality of filter members are provided in a collection chamber to remove blood clots and undesirable solids. A source of an anticoagulant may be provided in the collection chamber and in the collection bag.