The invention relates to a ventilation system for vehicle lighting systems having a housing opening with a protruding opening wall and a ventilation body, which is fixed to the housing opening by engagement with an inner part. The ventilation body and the housing opening have walls for forming a ventilation duct with a plurality of direction changes between an edge of the ventilation body and an aperture of the housing opening, wherein an inner part and an outer part which surround the opening wall of the housing opening have walls, which respectively sectionally lie circumferentially sealingly against the opening wall of the housing opening, and wherein the ventilation body and the housing opening are formed such that the ventilation body can be brought from an unlocked position into a locked position or vice versa by rotation according to a predetermined angle of rotation relative to the housing opening.