Polymer nanocomposites have been investigated as one of the light and suitable alternatives to lead clothing for protection against X-rays. The present study aims to fabricate flexible, lead-free, X-ray-shielding composites using a polyvinyl chloride matrix and different nanostructures. Four different nanostructures containing impure tungsten oxide, tungsten oxide (WO3), barium tungstate (BaWO4), and bismuth tungstate (Bi2WO6) were synthesized through various methods. Subsequently, their morphological characteristics were determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Two different weight ratios of these nanostructures (20% wt & 50% wt) were used to produce PVC composites. To investigate attenuation parameters, the prepared composites were subjected to X-ray irradiation at voltages of 40, 80, and 120 kV. The results showed that the PVC composites containing 20% wt Bi2WO6 had the highest linear attenuation coefficient (µ) at all three voltages. The incorporation of nanostructures would increase the attenuation coefficients. The Bi2WO6 composites with a weight ratio of 20% had the lowest half-value layer (HVL), tenth-value layer (TVL), and 0.5 mm equivalent lead thickness values at each of the three voltages. The PVC composites containing 50% wt Bi2WO6 had attenuation coefficients greater than those reported for PbO at each X-ray voltage. Therefore, this type of PVC composite is a suitable option for lead shields. Among the studied tungsten nanostructures, bismuth tungstate has good attenuation performance for X-ray protection. This material is also light, flexible, and non-toxic and can be suggested as an alternative to lead aprons.