Vanadium oxide (V2O5) mixed titanium oxide (TiO2) and zirconium oxide (ZrO2) thin films were fabricated on glass substrates (corning 2947) and on indium tin oxide (ITO) coated glass substrates by sol gel spin coating process. Their optical, structural and electrochromic properties were investigated. The results were compared with pure TiO2 and ZrO2 thin films. Mixture of V2O5 with both types of film reduces the transmittance at the higher wavelengths. The refractive index of the V2O5 mixed TiO2 and ZrO2 films increases when compared with pure TiO2 and ZrO2 films. AFM images demonstrate no significant topographical changes for V2O5 mixed TiO2 whereas for V2O5 mixed ZrO2 films a topographical change is observed. V2O5 mixed TiO2 showed slight increase in their charge capacity. (C) 2005 Springer Science + Business Media, Inc.