Abstract: A compressed air coupling with a coupling socket and a valve sleeve displaceable therein and lockable by a catch in the socket, and a nipple insertable into the valve sleeve and lockable by a ball catch in the valve sleeve. The valve sleeve (40) together with the nipple (16) is displaceable from its inner end position, while closing the connecting passage (58,64) to a predetermined intermediate position in which a passage (62,64,54,56) is opened between the nipple locked in the valve sleeve and the free atmosphere to release residual compressed air in the nipple.