An implement hitch is disclosed for a tractor having arms for attachment to an implement, wherein the arms have part-spherical sockets at their free ends for receiving coupling balls which during operation receive coupling pins on the implement to be connected by means of the hitch to the tractor. The hitch has lifting arms that are each movable by a respective hydraulic cylinder and are connected to the associated hydraulic cylinder by a linkage that incorporates at least one pivot pin. In the invention, at least one of the pivot pins has a projecting extension dimensioned to fit within the through bore of a coupling ball and a stop is provided on the extension to prevent a coupling ball supported by the pivot pin from sliding off the extension.