Composite ZnO/CeO2 thin films were grown epitaxially on r-sapphire substrates using the pulsed laser deposition technique. Their crystalline properties were established using x-ray diffraction and showed the ZnO (wurtzite structure) and CeO2 (fluorite structure) layers to be highly textured with the (20-23) and (100) orientations, respectively. Φ-scan measurements were also carried out and the (20-23)ZnO||(100CeO2), [1-210]ZnO||<011> CeO2 epitaxial relations established. The rocking curve profiles indicated that the ZnO films grew as four crystallographically equivalent domains. Series of rocking curve and χ-scan measurements at varying Φ angles, respectively, were used to investigate the domain structure. These showed that the normal to the (20-23) plane in each domain is tilted away from the substrate normal towards one of the four equivalent CeO2 <111> directions by ∼1.60. Atomic force microscopy measurements showed that the ZnO/CeO2 composite film has a granular microstructure with a rough surface (typical root mean square roughness of 7.9 nm). Low temperature photoluminescence spectra showed an intense near-band-edge emission at a photon energy of 3.361 eV, wi- th a full width at half maximum of 1.8 meV, testifying to the good optical quality of the ZnO material. The optical transmission of the ZnO/CeO2 composite film was measured in the 200–1000 nm spectral domain; it was completely opaque to UV radiation and became transparent with a sharp transition above 380 nm. Secondary ion mass spectrometry measurements were used for depth profiling of the ZnO/CeO2 composite structure. The corresponding data suggest that the CeO2 buffer layer acts as an efficient barrier against the diffusion of aluminum from the sapphire substrate into the ZnO layer.