Abstract: An oscillating sprinkler having improved provision for confining fluid discharge to a predetermined arc through which the sprinkler reciprocates, including a nozzle adapted to direct a stream along an axis in predetermined relation thereto, a pair of cooperative concave vanes; and means mounting the vanes in fixed spaced relation for integral movement to and from the stream with their concavities disposed toward a predetermined fluid path therebetween, one of the vanes being adjacent to the nozzle and having an inner end disposed theretoward in acute angular relation to the axis when in the stream and an opposite end curved laterally from the axis, the other vane being spaced laterally and longitudinally of the axis from said one vane in the direction of curvature thereof having an inner end substantially parallel to said opposite end of said one vane and an opposite end substantially parallel to the inner end of said one vane.