Abstract: A hydrotherapy jet assembly that produces rotating and pulsating streams of water and provides for user adjustable flow control, and user adjustable control of the speed of rotation independently of the flow control. The assembly includes a nozzle rotor supported for rotation in a generally cylindrical body, and a rotor retainer cage having a thrust plate that applies an axial retaining force to the rotor. The rotor has two internal passages that discharge water in directions that may be selected to produce a turning moment applied to the rotor. Fins may be incorporated into the rotor to produce or contribute to rotation. In all of the disclosed forms of the rotor, radial thrust components resulting from discharge of water through the two rotor passages cancel each other. The rotor is thereby balanced in directions transverse to its axis or rotation. Axial thrust components resulting from the discharge of water from the nozzle rotor are substantially balanced by the force of water entering the rotor.