The aim of this study was to determine the optical properties of WO, and Zr doped tungsten oxide films deposited by the sol-gel process. The optical properties of WO, and Zr doped tungsten oxide films deposited by the sol-gel process depend on the number of coating layers. The refractive index and absorption coefficient of WO, thin films increases with an increasing number of deposited layers. Transmittance of Zr doped tungsten oxide thin films are greater than tungsten oxide thin film. A scanning electron microscope was used for the analysis of surface structure. Optical constants of tungsten oxide and zirconium tungsten oxides were determined by using spectrophotometric transmissivity in the UV-Visible region.