Antimony-tin oxide (ATO) thin films were deposited using pulsed laser deposition. From a wide survey of deposition conditions (deposition atmosphere and substrate temperature), we deduced that the optimum experimental parameters to obtain electrochromic active films were a deposition temperature of 200degreesC at a 10(-2) mbar oxygen pressure followed by an annealing at 550 degreesC, the latter being critical. Through potentiostatic tests, we showed that depending on the composition, which influences film morphology, the Sn-Sb-O films could present either a faradic or a capacitive-like behavior, associated to a color or a neutral switching over a wide range of potentials, respectively. In addition, a relationship between the film annealing temperature and its structure as well as its electrochromic properties was evidenced by means of complementary electrochemical, X-ray diffraction and electron microscopy techniques. Finally, the electrical and optical properties of the ATO films were discussed in terms of the energy band theory. (C) 2003 Elsevier Science B.V. All rights reserved.