Sol-gel derived tungsten oxide (WO3) films were deposited using acetylated peroxotungstic acid as the precursor material adopting sol-gel dip coating route, followed by thermal treatment at 500 °C in air for 3 h. Structure-microstructure investigations of these films using X-ray diffraction and transmission electron microscopy techniques revealed the films to exhibit nanorods as the major microstructural feature with combined nanowires and nanoparticles as a minor constituent. The kinetic mechanisms responsible for the formation of nanorods have also been elucidated. Both the nanorods and the particles exhibited a pseudocubic triclinic crystal structure. © 2006 Elsevier B.V. All rights reserved.