This paper focuses on the preparation and characterization of crystalline thin films of rare-earth-doped sesquioxides (Y2O3 and Lu2O3) grown by pulsed laser deposition on single-crystal (0001) sapphire substrates. The crystal structure of the films (thicknesses between 1 nm and 500 nm) was determined by X-ray diffraction and surface X-ray diffraction analysis. These measurements show that the films were highly textured along the <111> direction. Using Rutherford backscattering analysis the correct stoichiometric composition of the films could be proved. The surface morphology of the thin films has been studied using atomic force microscopy. Crystalline films show a triangular surface morphology, which is attributed to the <111> growth direction. The emission and excitation spectra of the Eu-doped films down to a thickness of 100 nm look similar to those of the corresponding crystalline bulk material, whereas films with a thickness ≤ 20 nm show a completely different emission behaviour.