This work is an attempt to develop flexible radiation shielding based on a blend of polymethyl methacrylate (PMMA)/polyvinyl acetate (PVAc) and LaFeO nanoparticles (NPs). LaFeO and LaFeO/PMMA/PVAc were made using simple chemical techniques. A high-resolution transmission electron microscope (HR-TEM) and X-ray diffraction (XRD) showed that well-crystallized LaFeO NPs with particles 79 nm in size and an orthorhombic shape were obtained. In addition, XRD confirmed the existence of PMMA, PVAc, and LaFeO in the nanocomposite films. Fourier transform infrared (FTIR) confirmed that the LaFeO NPs and the reactive functional groups in the blend interacted with each other. Field emission-scan electron microscope (FE-SEM) analysis showed that PMMA and PVAc form a homogenous blend and that the LaFeO NPs were spread out inside and on the blend surface. The samples showed transmittance in the range of 30-74% and a small extinction coefficient (≤ 0.08). The samples exhibited a dual-band gap structure, and the direct (indirect) band gap shrank from 5.1 to 4.7 eV (4.9 to 4.4 eV). The thermal analyses showed that the samples are thermally stable up to 260 °C. The Phy-X/PSD software was used to figure out the theoretical gamma-ray attenuation parameters, such as the mass attenuation coefficient, the mean free path, and the half-value layer, for different PMMA/PVAc + x% LaFeO composites. It is demonstrated that the PMMA/PVAc + 10 wt% LaFeO sample exhibits much better shielding effectiveness than PMMA/PVAc, and hence it is suitable for protecting against radiation.