Abstract: A three-way fluid mixing valve as provided with a valve body having a mixing chamber in communication with an outlet passage and two inlet passages, the two inlet passages opening into the chamber through opposed, axially aligned inlet ports. A cylindrical stem is guided by the valve body for angular movement about the stem axis and rectilinear movement along the axis and supports a cage in the mixing chamber. The cage has two spaced-apart planar valve members each defining an orifice therethrough disposed so as to be movable into and out of registration with one of the inlet ports in two mutually perpendicular directions in a plane of movement extending parallel to the associated inlet port. The cage is mounted on a stem for vertical movement with the stem and the stem has a camming shaft received in a cam follower slot in the cage for effecting reciprocating movement of the cage within the chamber when the stem is rotated by suitable handle means.