A modular guard system for a power saw includes a riving knife mounted to the saw rearwardly of the blade and having first and second notches with openings facing away from each other. A blade guard assembly is releasably mounted on the riving knife and configured to cover the blade. The blade guard assembly includes a mounting portion configured to receive a top portion of the riving knife having the first and second notches and a release mechanism provided in the mounting portion and having a spring member for engaging the first notch and a latch member connected to the spring member for engaging the second notch. The latch member exerts a force on the spring member to cooperatively hold the first and second notches between the spring member and the latch member to retain the riving knife in the mounting portion.