Indium oxide (In,Os) thin films have been prepared by spray pyrolysis using a very low concentration of indium precursor. The spray process parameters like the concentration of precursor in spray solution, ethanol+water, air-flow rate. substrate-nozzle distance and substrate temperature have been optimized for obtaining optically transparent, conducting and device-quality In2O3 films. The material properties are reported by studying the structural, electrical and optical properties of the In2O3 films prepared at a relatively lower temperature of 380degreesC. The surface morphology has been studied by scanning electron microscopy and atomic force microscopy. A possible film growth mechanism has been proposed for preparing device-quality In2O3 films using lower substrate temperatures. (C) 2002 Published by Elsevier Science B.V.