(Gd1– xTbx)2O3 (x = 0.04–0.22) films 115 to 150 nm in thickness have been grown on Si and SiO2 substrates by metal organic chemical vapor deposition (MOCVD) using Ln(dpm)3 precursors. After annealing in air at 800°C for removing carbon-containing impurities, the films were sulfided in NH4SCN vapor at temperatures from 700 to 1000°C in an Ar atmosphere until the formation of (Gd1 –xTbx)2O2S oxysulfides. The surface of the films is formed by grains 60 to 200 nm in size. The measured refractive index of the films is 2.2–2.4 and their estimated optical band gap (Eg) is 4.7–5.0 eV. The optical transmission of the films in the visible spectral region (400–750 nm) reaches 78–84%. The highest photoluminescence (PL) intensity in the oxysulfide films produced under identical conditions has been observed at x = 0.05. The blue component of their PL decreases with increasing terbium content and the emission shifts to the green spectral region.