A comprehensive study of structural modifications of gamma irradiated polymers in the dose range of 101 Gy to 106 Gy, was conducted using FT-IR technique. The results were varied in nature, proving that all polymers do not undergo similar type of destruction under similar irradiation conditions. The IR spectrum of polypropylene polymer confirmed the total destruction of isotactic arrangements of the polymer. The destruction of the polypropylene polymer lead to the formation of alcoholic and ketonic groups. For polyacetate polymer, elimination of carbon dioxide took place due to destruction of the ester group. Interestingly, for polycarbonate polymer also, it was observed that at the dose of 106Gy, phenolic group formed due to cleavage of ester bonds. For polyvinyl chloride, there was a clear spectral indication regarding the formation of C=C bond and simultaneous decrease in concentration of C-Cl bond which took place upon gamma irradiation.