A medical fluid pump, comprising a first, inner fluid system including a motor-driven suction/pressure unit and a first fluid pressure chamber which can be filled with fluid and emptied by the suction/pressure unit, and a second, outer fluid system including a second fluid pressure chamber which is coupled to the first pressure chamber in a pressure- and/or volume-dynamic manner via a movable separating wall and which is alternately coupled—via a valve means of the second fluid system—to a suction line and pressure line depending on the current working phase of the suction/pressure unit of the first fluid system is disclosed.