The goal of this study was to investigate the optical properties of the prepared polyvinyl chloride (PVC)/zinc oxide (ZnO) nanocomposite films. The PVC/ZnO nanocomposite films consist of the addition of different concentrations with both non-annealed ZnO nanoparticles and ZnO nanoparticles annealed at temperature of 700°C. The PVC/ZnO nanocomposite films by weight concentrations of (0 wt.%, 2.5 wt.%, 5 wt.% and 10 wt.%) have been prepared by the casting method. The optical absorbance and transmittance values of the composites films were measured in the wavelength range between (250 to 1100 nm) at room temperature by using the UV-1800 Shimadzu spectrophotometer. The optical properties (absorption coefficient, dielectric constant, refractive index, and optical conductivity) have been investigated by the ultraviolet (UV) spectrophotometer. The optical parameters (direct optical energy gap, excitation energy for electronic transitions, the dispersion energy, static refractive index, static dielectric constant, optical oscillator strengths, the moments of optical spectrum, linear optical susceptibility, third-order nonlinear optical susceptibility, nonlinear refractive index, high-frequency dielectric constant, the carrier concentration to the effective mass ratio, the long wavelength refractive index and the plasma frequency) were calculated. The results showed that the optical properties behavior of the PVC/ZnO nanocomposite films was found to be dependent on the ZnO concentration, and photon wavelength. In addition, the results of the study show that the optical parameters can be influenced by alter the concentration of the nonannealed and annealed a ZnO nanoparticle in the PVC polymer matrix.