A photoluminescence study of ZnSe‐ZnSxSe1−xstrained‐layer superlattices withx=0.19 grown by molecular beam epitaxy is presented. We observe clear shifts of the excitons to higher energies as the well widths are reduced. These shifts are interpreted in terms of quantum confinement effects using the envelope function approach and the strain‐induced effects using the deformation potential theory. From our analysis we conclude that most of the band offsets between ZnSe‐ZnSxSe1−xare taken up by the valence bands.