A sliding door system includes a rail device with a mounting rail mountable in a building, with a guide rail in which at least two carriages that are connected to a sliding door are held displaceable along a guide axis, and with a plurality of coupling devices with which the guide rail and the mounting rail are releasably connected with one another and which comprise a coupling head connected to the guide rail or the mounting rail, that comprises a coupling plate and a coupling neck and that can be anchored in a coupling opening provided in the mounting rail or the guide rail and which comprises a first opening part with a diameter larger than a diameter of the coupling plate, and a second opening part adjacent thereto with a diameter larger than the diameter of the coupling neck but smaller than the diameter of the coupling plate.