Abstract: A portable doweling jig includes a generally cuboidal body comprising four sets of bores that facilitate the drilling of precisely positioned holes into workpieces for receiving standard-sized construction dowels. Despite the absence of moving parts, the present invention accommodates dowels of different diameters, and also workpieces of both standard and nonstandard thicknesses. Furthermore, the present invention makes possible the creation of three types of dowel joints: edge-to-surface, edge-to-edge, and surface-to-surface.