Films of Poly ( vinyl chloride) (PVC) doped with different concentration of nanosize zinc oxide (ZnO) (1-20) what% have been prepared using the casting method at room temperature. Optical properties were investigated by spectrophotometric measurement of absorption, reflection and transmission in the wavelength range (200-800) nm from computerized UV-visible spectrophotometer (Shimadzu UV-1601 PC). Both the absorption coefficient and energy gap were determined for the films. It has been found that the optical properties of PVC are affected by the doping of ZnO. The Reflection and absorption coefficient has increased as ZnO concentration increased, but the energy gap was decreasing with these increments from 3.9 to 3.8 eV.