Abstract: A coupling device for hitching a trailer to a vehicle such as an agricultural tractor comprises a frame for attachment to the underside of the vehicle, and a guideway carried by the frame which can be moved (e.g. pivotally) downwardly when the frame is attached under the vehicle. The guideway is adapted to receive and guide a trailer-mounted tow-bar assembly from a rearward to a forward location. When in the forward location, which is preferably in front of the vehicle's rear axle, latching means can be actuated to lock the tow-bar assembly in its forward location. The latching means can be actuated by upward movement of the guideway. The coupling device includes provision for pitch, roll and yaw movements between vehicle and trailer.