Indium tin oxide (ITO) thin films with various thicknesses from 170 to 700 rim have been grown onto unheated glass substrates by sputtering from ceramic target, and subsequently annealed in vacuum at temperatures ranging from 250 to 350 degrees C. The structure, morphology and electro-optical characteristics of the ITO samples have been analyzed by X-ray diffraction, atomic force microscopy, four-point electrical measurements and spectrophotometry. Polycrystalline ITO growth has been found varying with film thickness. The thickness also determined the recrystallization achievable by annealing and the electro-optical thin film properties. (c) 2005 Elsevier B.V. All rights reserved.