Armrest device, in particular for commercial vehicle seats, having a guide rail system for guiding a displacement movement of a first rail relative to a second rail which can be connected to the armrest device, in a displacement direction, wherein the displacement movement of the first rail can be arrested by the engagement of a locking element of a locking device in at least one recess in the first rail, wherein the locking device is rigidly connected to the armrest device by a first end and can be deflected in a height direction by a second end, the locking element engaging in the recess in a non-deflected position of the locking device.