An illumination system, in particular for illuminating tiled wall protrusions, includes at least one elongate, substantially U-shaped profile that has a base arm and two side arms projecting from the latter and arranged lying opposite one another, the first side arm being made longer than the second arm, at least one illuminant that is fastened or can be fastened within the receiving space defined by the base arm and the two side arms of the profile, and at least one elongate diffusion disc cover fastened or that can be fastened to the profile.