This study addressed the limitations of lead-based radiation shields by developing lead-free, non-toxic, lightweight, and flexible shielding materials with high attenuation efficiency. To achieve this, single and triple layers of Bi2O3-BaTiO3/PVP-PEG nanocomposite films were synthesized. Polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) polymers (2:1 ratio) were used as the polymeric matrix in which fillers of Bi2O3 and BaTiO3 nanoparticles (NPs) with particle sizes ranging from 90 to 210 nm and <100 nm, respectively, were embedded. Four single-layer samples with 20%, 30%, 40%, and 50% NP concentrations were prepared; the samples were 1.05, 1.09, 1.27, and 1.42 mm thick, respectively. Two samples of triple-layered films were prepared with 30% and 50% NPs, measuring 3.78 and 4.23 mm in thickness, respectively. The attenuation efficiency of these films was investigated using X-ray tube voltages from 10 to 120 kVp. Further, the flexibility of the synthesized films was tested by manual handling. All single- and triple-layer nanocomposites exhibited effective radiation attenuation and desirable flexibility. Specifically, at the lowest tube voltage, all samples exhibited 100% attenuation, while at the highest tube voltage, the attenuation ranged from 27% to 84%, depending on the NP concentration and number of layers of the sample. The highest attenuation ratio, observed in the 50% triple-layer sample, reached 100% up to approximately 60 kVp and 84% at 120 kVp. Consequently, the most optimal film synthesized in this study had a triple-layer configuration with 50% Bi2O3-BaTiO3 NPs embedded in a PVP-PEG polymer with an average attenuation of 95.5% for all tube voltages (10–120 kVp). Therefore, this shielding is suitable for various diagnostic applications, such as mammography, dental X-rays, computerized tomography, and fluoroscopy. Highlights Single- and triple-layered nanocomposite Bi2O3-BaTiO3/PVP-PEG films were synthesized The attenuation efficiency of the films against X-rays was investigated A triple-layer configuration with 50% Bi2O3-BaTiO3/PVP-PEG was suitable for various diagnostic applications