Mixed V2O5-MoO3 thin films were deposited onto the glass and fluorine doped tin oxide (FTO) coated glass substrates, at 400 degrees C by pulsed spray pyrolysis technique (PSPT). Equimolar vanadium chloride (VCl3) and ammonium molybdate aqueous solutions were mixed together in volume proportions (5-15% molybdenum) and used as a precursor solution for the deposition of mixed V2O5-MoO3 thin films. The structural, morphological, optical and electrochromic properties of the films deposited at different Mo concentrations were studied. With increase in the percentage of Mo the peaks belonging to tetragonal phase of V2O5 eventually disappear and the (1 0 1) orthorhombic V2O5 phase is observed. Scanning electron microscopy (SEM) shows micro thread like reticulated morphology. The optical band gap energy varied over 2.91-2.85 eV. All the films exhibited cathodic electrochromism in lithium containing electrolyte (0.5 M LiClO4 + propylene carbonate (PC)). The highest coloration efficiency (CE) for the V2O5 film with 15% MoO3 mixing was found 35.27 cm(2) C-1. (C) 2010 Elsevier B.V. All rights reserved.