The interest of this work is to improve the gamma-ray shielding capacity of polyepoxides resin using tungsten trioxide (WO3). Therefore, the polyepoxides resin is partially substituted by the WO3 compound to produce three tungsten-doped polyepoxides samples with WO3 concentrations between 0 and 10 wt%. The measurement of the density of the fabricated composite showed an enhancement in the density of the composites from 1.103 g/cm3 to 1.197 g/cm3 by raising the WO3 concentration between 0 and 10 wt%. The distribution of the WO3 compounds inside the polyepoxides resin is affirmed using the scanning electron microscope. Moreover, in order to identify the performance of WO3 on polyepoxides to boost the radiation shielding strength the γ-ray shielding parameters such as linear attenuation coefficients, and transmission factor have been evaluated using The Monte Carlo simulation in γ-ray energy interval between 59 and 1408 keV. The results demonstrated that the linear attenuation coefficient of the fabricated composites enhanced with enrichment of WO3 content where the μ values enhanced by a factor of 141% (at 59 keV), 23% (at 305 keV), 10% (at 661 keV), and 7% (at 1408 keV) when the WO3 concentration increased between 0 and 10 wt%. Hence, it can be stated that the additives WO3 enlarge the shielding ability of polyepoxides in the γ-ray energy below 661 keV.