A dual-knife device for scribing or scoring a wood workpiece before sawing it with a motorized circular handsaw or other saw. The scoring insures a clean saw cut without splintering the wood at the edges, as is required in trimming veneer doors and wall panels. A guide bar is clamped to the workpiece to guide the saw and the scoring device. Prior to sawing, the scoring device is drawn by hand across the workpiece, guided by the same guide bar. The scoring device comprises a pair of knife blades mounted close together on a frame. The knife blades cut two parallel scribe lines or scores into the wood surface, one on each side of the kerf to be sawed. When the saw cut is made, the score lines prevent the saw blade from splintering or feathering the surface of the workpiece along the kerf line, insuring a clean cut.