An illumination device (1) for a motor vehicle headlight, including illumination units arranged next to one another, which respectively have a light source, primary optical device, and a secondary optical device. The primary optical devices are held in a common holding element formed by a transparent body. In the body, an overcoupling protective device in the form of a through hole in the body is provided between two adjacent receiving through holes in which a primary optical device is respectively held. The through hole of the overcoupling protective device is delimited by two side faces, which face the receiving through holes of the primary optical devices. Light deflection means are designed to deflect at least part of the rays of light entering the body such that part of the rays of light does not enter the adjacent illumination unit or strike the secondary optical device of the adjacent illumination unit.