Abstract: The disclosure relates to an improved static mixing nozzle, suited particularly for use in systems for delivering viscous molten plastics, for injection molding and like processes, but useful to good advantage in the mixing of other flowable materials, dry, liquid and gaseous. The mixing nozzle includes a cylindrical, tubular nozzle housing having inlet connection means for coupling with a plastic extruder or the like and a discharge nozzle at the opposite end. Within the cylindrical housing is a mixing element in the form of a cylindrical plug. The plug is provided with a plurality of sets of through bores, which extend at an angle from one side wall to the other, passing through the center axis of the plug. There are several stages of such bores, and each stage includes a plurality of mutually intersecting bores, which meet at the central axis of the plug.