The work deals with the synthesis of new epoxy composites doped with ZnO nanoparticles. The radiation shielding performance for the synthesized epoxy-doped ZnO nanoparticles was measured experimentally using the narrow beam transmission technique. The method was performed using NaI (Tl), Cs-137, and Co-60 radioactive sources. The linear attenuation coefficient (μ) for the synthesized samples enhanced from 0.090 cm−1 to 0.094 cm−1 by raising the ZnO nanoparticles from 0 to 20 wt%, respectively. The experimental measurement showed only an enhancement in the μ values by a factor of 4.4% at 662 keV with a high uncertainty between the experimental measurement and Monte Carlo simulation reaching 9.8%. © 2023 Elsevier Ltd