Abstract: A mitering apparatus for frames or moldings includes a base plate on which mitering saw guides and a pair of work holding vises or clamps are mounted. Each clamp has a fixed and a movable jaw and the two clamps are mountable on the base plate for either a standard 45.degree. cut or for a 30.degree. or 22-1/2.degree. cut in some instances. Guideways for the two clamps or vises are provided on the base plate for coaction with a pivoted clamp adjusting lever and links which interconnect the lever with the clamps so that they may be adjusted bodily in unison and oppositely along linear paths to assure perfect alignment of the mitered ends of molding sections or other work prior to joining by means of nails or glue. Realignment of the joint is also possible if slippage of parts should occur during nailing. It is unnecessary to unclamp the work sections or loosen the movable clamp jaws to effect proper alignment or realignment of the work.