Abstract: Disclosed is a doweling jig which allows a workpiece to be positioned on the top surface of a platform to guide the drilling of corresponding holes into the workpiece at preselected locations. The workpiece-supporting platform includes a pair of side edges and a guideway which extends along the edges. A plurality of drill guides, each of which includes a guide opening, is removably engageable with the guideway to be positionable at preselected locations along either of the side edges. The workpiece may be positioned on the platform and against the drill guides for the drilling of holes in the workpiece through the guide opening in each drill guide. The jig may be configured to allow for simultaneous drilling of holes in two or three adjacent surfaces of the workpiece.