A composite semiconductor light-emitting device includes a first semiconductor element portion made of a first semiconductor material and a second semiconductor element portion made of a second semiconductor material different from the first semiconductor material. The first semiconductor element portion has a first semiconductor layered structure, and the second semiconductor element portion has a second semiconductor layered structure. The first semiconductor element portion has a plurality of light-emitting regions that emit lights of different wavelengths. The second semiconductor element portion has at least one light-emitting region that emits light whose wavelength is different from the lights emitted by the light-emitting regions of the first semiconductor element portion. The light-emitting regions of the first semiconductor element portion and at least one light-emitting region of the second semiconductor element portion are electrically connected to each other.