Trailer coupling

The trailer coupling has a coupling element (1) on the vehicle and a mating coupling element (2) on the trailer. The mating coupling element is locked by means of a holding down device (3) in relation to the coupling element on the vehicle. The holding down device is transferred from its open position to its closed position, and vice versa, by a sideways swinging. The swinging movements of the holding down device are carried out around a vertical axis in a preferably horizontal traction plane.