Thin YAG:Ce3+ films were synthesized by pulsed laser deposition. For the first time, the dependences of the thickness, phase composition, and photoluminescence of films on the substrate temperature during synthesis were studied. It is shown that, regardless of the synthesis temperature in the range of 100-400 °C, the resulting films had a polycrystalline structure. With an increase in the substrate temperature, an increase in the film growth rate was observed. Despite the polycrystalline structure of the films, after annealing at 900 °C, YAG:Ce3+ thin films exhibited pronounced photoluminescence, which opens up the possibility of their application as modifying coatings for photoconverters, as well as for X-ray detectors.