Abstarct: This thesis investigates the influence of zinc oxide (ZnO) nanoparticle concentration on the gamma-ray shielding properties of polyethylene-baxsed nanocomposites using 241Am and 137Cs sources. Samples containing various weight percentages of ZnO were fabricated, and key shielding parameters—including the linear and mass attenuation coefficients, half-value laxyer (HVL), and mean free path (MFP)—were determined both experimentally and through theoretical calculations using the XCOM databaxse. The findings indicate that increasing the ZnO content enhances the attenuation capacity of the nanocomposites, thereby improving their shielding efficiency. A comparative analysis between experimental and theoretical data showed good agreement, with relative errors remaining below 10%, confirming the reliability of the applied measurement methods and computational models. These results suggest that ZnO/PE nanocomposites are promising candidates for gamma-ray shielding in industrial and medical environments.