Abstract: A pipefitter's jig for facilitating the coupling of a length of pipe to a pipe fitting comprises a base on which any one of a number of different blocks may be mounted, each block being recessed to conform to the configuration of the fitting and pipe to be coupled. Guide means is carried by the base for supporting a length of pipe in predetermined relation with reference to the pipe fitting and is movable toward and away from the fitting so as to adjust the relative positions of the fitting and the pipe.