Abstract: A lighting device is disclosed, in particular for installation behind a flat wall or ceiling element. Further provided is a lighting assembly wherein the wall or ceiling element comprises a first light passage opening, and the lighting device is arranged on a rear side of the wall or ceiling element such that the focal point is located in the first light passage opening and/or in the plane of a front side of the wall or ceiling element opposite the rear side, whereby the lighting device contacts the rear side of the wall or ceiling element in particular flatly.