Abstract: A guide for cutting a truss joist I-beam with a hand-held power saw such as a worm drive, hypoid drive, or circular saw is disclosed. The guide comprises a base positionable along a top surface and an inner edge of one chord of the I-beam, a mechanism mounted on the base for securely holding the base to the chord, and a cutting guide pivotally mounted on the base for guiding a hand-held power saw at a selected angle in cutting the I-beam. The holding mechanism includes a handle extending from the base and a pivot arm pivotally coupled to the base. The pivot arm has a gripping end for contacting the chord and a pivot handle for pulling upwardly toward the handle for causing the gripping end to pivot into contact with the chord.