Abstract: A carton flap opening assembly for use in a carton conveying apparatus having a frame and a conveyor. The assembly includes a horizontally disposed arm having a mounting portion at one end and a flap engaging portion extending therefrom. The flap engaging portion has a generally planar trailing edge section at its outer end, and a depending arcuate leading edge portion with an upwardly extending end section therebehind. A rotating mechanism has mounting means supporting the mounting portion of the arm for rotation of the arm about a vertical axis spaced to one side of the conveyor path. A vertical motion mechanism supports the rotating mechanism and thereby the arm for movement vertically relative to the plane of the associated conveyor path and a control mean for operating the rotating and vertical motion mechanisms in response to the position of a carton moving along the conveyor path.