A self-aligning coupling for lift guides, which consists of a core-mushroom element and wings. Each wing carries a through hole in its coupling zone and there are: under the wings an extra-flat plate provided with four through holes in correspondence with the orifices of two guides to be joined; on top of the wings, two extra-flat plates, each provided with two through holes in correspondence with two orifices of two guides to be joined. in said orifices, and retaining screws fastened with nuts; said screws presenting a conical head. The orifices of the plates are of greater diameter than the orifices of the wings.The distance between the orifices of the plates is shorter than the distance between the two orifices of the wings of the same side.