The effect of Li (0-5 wt%) doping on the properties of WO3 thin films deposited using an automated homemade spray pyrolysis unit is studied. Change in structural and optical properties is observed on doping with Li. The XRD patterns shows that undoped WO3 film has an orthorhombic phase while the Li (1-5 wt%) doped WO3 films have tetragonal phase. The SEM and AFM images confirm relatively smooth surface of Li doped WO3 films compared to undoped WO3 film. Transmission spectra reveal that the transparency of the Li-doped films is much greater than that of undoped film. From the transmission data, the direct, indirect bandgap and phonon energies were calculated. Room temperature photoluminescence spectra showed pronounced blue emission on doping with Li. (C) 2011 Elsevier B.V. All rights reserved.