Electron beam irradiation can be used to improve the physical and mechanical properties of polymers. The aim of this study was to investigate the influence of electron beam irradiation with an energy dose up from 5 to 50 kGy on the Fracture toughness property of polymer denture base resins. The four different denture base resins used in study are DPI, Trevalon, Trevalon HI and Meliodent heat activated acrylic resins. The influence of electron beam post-curing on Fracture toughness of the polymer denture base resins was investigated. The irradiated denture base resins were compared with untreated control groups. It has been demonstrated that the Fracture resistance of mostly PMMAbased denture resins could be improved using electron beam irradiation only up to 25 kGy, although as the radiation dose increases above 25kGy toughness get reduced. It appears that during irradiation, C–C bonds are split off and the polymeric structure starts to break down after certain dose of radiation. The findings of the present study demonstrate that all the investigated denture base resins show improvement in mechanical properties that is fracture toughness.