A picture hanger has an upper piece, a lower piece, and a screw that extends through apertures in shelves on bases of the pieces. The aperture on the lower piece has threads mating with the screw threads on the shaft so that when the upper piece is fixedly mounted on the vertical surface by an elongated fastener the lower piece is held in place only by the threads of the shaft engaging the threads in the aperture on the lower piece shelf. The base of the lower piece carries a picture wire receiving hook so that turning the screw enables the height of the picture to be changed. Strengthening ribs extend between the base and shelf of both pieces.