In this work, we present a sot-gel method for the preparation of zirconia films. Using zirconium n-propoxide as the starting precursor, a ZrO2 sol has been synthesized that remains stable for several months. Thin films were deposited using the dip-coating method. The structural characterization was performed using waveguide Raman spectroscopy. The films present an amorphous phase up to all annealing temperature of 400 degrees C. Both monoclinic and tetragonal phases were obtained for annealing temperatures higher than 450 degrees C. The proportions of these two phases were calculated from the Raman spectra and the size of the crystallites was evaluated using the low-wavenumber Raman band. The optical properties were characterized by the m-lines technique (n = 1.96) and UV-visible spectroscopy. The optical losses for a TE0 mode were measured to be 0.29 +/- 0.03 dB cm(-1) for a sample annealed at 400 degrees C. To optimize the protocol for thermal annealing, a powder obtained from a dried sot was characterized by Thermal Gravimetric Analysis. Rutherford Back Scattering was employed to determine the chemical composition and the stoichiometry of the zirconia films. (c) 2005 Elsevier B.V. All rights reserved.