High-quality Zn 0.85 Cd 0.15 Se/ZnSe single quantum wells (SQWs) have been fabricated on GaAs(110) crystal surfaces which were obtained by cleaving GaAs(100) wafers in ultra high vacuum (UHV). The growth interruption was found to prevent the growth of high-quality quantum well structures. The (110)-oriented SQWs grown under appropriate conditions show a very sharp photoluminescence spectrum whose full width at half-maximum (FWHM) is as small as 4.9 meV. The sample showed a strong in-plane polarization angle dependence of the emission intensity, due to the compressive strain in the well layer. The ratio of maximum to minimum values of the polarized PL intensity was 1.6.