Abstract: The smoking attachment for use with a barbecue grill has a smoker box with a solid bottom plate, left and right side walls, a rear wall, a top, an open front and two doors that close and substantially seal the smoker box. Support brackets on the side walls support the smoker box on a grill box with the solid bottom plate above a grill heat source. A smoker box divider plate divides the smoker box into a wood chip chamber and a smoking chamber. A wood chip box holds wood chips and sets inside the wood chip chamber. Tray and rack holders support racks and trays with food products in the smoking chamber. Smoke from the wood chips passes through smoke passages in the smoker box divider plate and through smoke passage apertures in the tray and rack holders. Vertical smoke baffles on the tray and rack holders control the distribution of heat and smoke.