The power saw cutting guide consists of a guide plate and preferably means to secure the guide plate against a workpiece to be cut. This securing means may include a press plate which may be bolted together with the guide against a workpiece. The guide plate is adapted to be cut to size by the first cut of a power saw guided thereby and will thus be peculiarly adapted to that particlar power saw. To facilitate this function, at least the outer extremities of the guide plate spaced from a saw guiding shoulder are formed of a material which may be easily cut by a power saw guided thereby.