Thin transparent films of poly(vinyl alcohol)/hydroxypropyl cellulose (PVA/ HPC) (0/100, 92/8, 88/12, and 0/100wt/wt%)were prepared by using solutioncast technique. The effects of HPC concentration on the optical characterizations by analyzing the transmittance spectra in the spectral region 200Â900 nm as well as the variations in the group coordination by using FTIR technique in the region (4000-1000 cm-1) of the prepared PVC/ HPC blends have been done before and after irradiation with two fast neutrons fluencies (1 x 105 and 1 x 107 n/cm2). The study has been extended to include the changes in the optical parameters including the band tail width and band gap energies for the samples. The results noticed that the optical band gap was derived fromTaucÂs extrapolation and increases with the HPC contents. Also, the results obtained by the FTIR indicate that the increase in the concentration of HPC with PVAchanged the chemical bonds and hence changed the molecular configuration of PVA. Moreover, the results obtained by the effect of different weight percent of HPC were compared with that detected by the effect of fast neutrons.