The deposition of CeO2 films on fused-silica substrates by spray pyrolysis of a water-ethanol solution of a cerium nitrate precursor has been studied. Polycrystalline films have been obtained at a substrate temperature of 300-450°C after annealing of the deposit in air at temperatures in the range 350-500°C. It has been established that the best uniform ceria films with nanometric scale grains are prepared at a substrate temperature of 400°C with 0.5 h annealing of the deposit at 500°C. At lower spraying temperatures large CeO2 crystallites have been observed on the film surface along with the fine grains. When the substrate temperature exceeds 400°C, numerous cracks caused by thermal stresses appear in the films. (C) 2000 Elsevier Science Ltd.