Amorphous SnO2 thin films have been deposited using different spraying times via the spray pyrolysis method. The structure of the films was analyzed by X-ray diffraction and the results obtained showed that the structure of the films was almost non-crystalline. The optical properties of these thin films have been investigated by means of optical transmittance and reflectance spectra. The dispersion of the refractive index is discussed in terms of the Wemple-DiDomenico single oscillator model. The optical band gap E-g, the width of band tails of localized states into the gap E-U; the single oscillator energy E-o, the dispersion energy E-d and the optical constants such as refractive index, extinction coefficient, dielectric constant and optical conductivity were estimated.