Abstract: An extensible hitching device for road and rail vehicles is provided comprising a hydraulic actuator (4) having a cylinder (5), a piston (6), a piston rod (15) and a chamber (7) containing a hydraulic fluid; a coupling device (17) adapted for connection to the rear of another vehicle; resilient means urging the coupling device towards the other vehicle; a hydraulic circuit comprising a reservoir (25) connected to the chamber (7) through two ducts (26, 27), one comprising a normally closed valve (28) and the other a hydraulic pump (30); detection means for controlling opening of the valve (28) when the two vehicles, in the hitched position, form therebetween an angle greater than a given angle, and allowing the resilient means to cause the coupling device (17) to extend while driving back into the reservoir (25) the hydraulic fluid contained in the chamber (7) and control means for actuating the pump (30) so that the fluid driven thereby back into the chamber (7) causes the coupling device (17) to retract agai