A lattice-mismatched ZnTe epilayer on a GaAs(100) substrate was grown by the simple method of temperature-gradient vapor deposition. X-ray diffractometry measurements were performed to investigate the structural properties of the ZnTe layer. Raman spectroscopy measurements showed that there was a lattice mismatch between the ZnTe epitaxial layer and the GaAs substrate. Reflectivity and photoreflectance measurements clearly revealed the splitting of the valence-band maximum, and photoluminescence measurements showed several resonant excitations of the ZnTe. The binding energies of the light holes and heavy holes determined from the splittings are in reasonable agreement with the bulk values.