The main principle of radiation protection is to limit radiation exposure or reduce the value of this exposure as much as possible. One of the most important means used to reduce the value of radiation exposure is the use of radiation shield, which are used to contain radioactive sources or create radiation barriers. The design and selection of appropriate materials for radiation shields depend on the type of radiation and its energy. The current work aims to study the fast neutron shielding using unsaturated polyester composite reinforced with glass. Shielding against fast neutrons remains a critical challenge in radiation protection due to their high power and the inefficiency of conventional materials (e.g., concrete, lead) at manageable weights. Polymer-glass composites emerge as a promising solution, combining the lightweight flexibility of unsaturated polyester with the neutron moderation and absorption capabilities of glass reinforcement. Fast neutron shields were manufactured using unsaturated polyester as a base material with different concentrations of ordinary glass and boron-reinforced glass as reinforcement materials with different concentrations (10%, 20%, 30%, 40% and 50%) and a thickness of 1 cm. For this purpose, the Am-Be neutron source with a neutron flux of 3x105(n/cm2.s) was used. Some shielding properties such as the macroscopic cross-section, half-thickness and mean free path were measured to determine the efficiency of the manufactured shields. The results showed that with increasing the concentration of the reinforcement material, the macroscopic cross-section values increased while the half-thickness and mean free path values decreased. The results also showed that boron-reinforced glass exhibits better shielding properties than ordinary glass due to its content of boron, which is a good neutron absorber.