Abstract: A jig for mounting workpieces which are to be doweled together, with the jig including two workpiece receiving spaces disposed one above the other and separated by a spacer member. Flat sides of the workpieces are adapted to be clamped against the spacer member with front edge surfaces thereof being brought into abutment with a base plate of the jig. At least one drill accommodating hole communicates with the receiving spaces for the workpieces for enabling of a drill accommodating hole in the workpieces. At least one additional drill hole, communicating with the other workpiece receiving space is provided in the base plate at the same distance from the spacer member as the first drill accommodating hole and in the same vertical plane so as to enable the use of the jig for a front to front side doweling of the workpieces.