Pb3O4 nanoparticles were embedded in a Polyvinyl chloride (PVC) polymer matrix with different filler ratios 0, 1, 2, 3 and 4 wt%. The nanocomposite films are prepared at room temperature via solution-casting technique. XRD analysis showed that pure PVC film is partially crystalline and Pb3O4 nanoparticles have a tetragonal crystal structure. TEM revealed nearly spherical Pb3O4 nanoparticles with average size around 24.3 nm which is very close to that obtained from XRD. Scanning electron microscopy micrographs indicated a PVC film with uniform surface morphology and Pb3O4 nanoparticles are well dispersed on the PVC surface. The optical band gap, Eopt, values calculated from optical absorption spectra decreased from 5.05 to 4.34 eV with increasing Pb3O4 wt%. Also, both Fermi energy, EF, and Urbach energy, ∆E, increased with increasing Pb3O4 filler content. The addition of Pb3O4 nanoparticles increases the solar material protection factor (SMPF) from 99.89 to 99.99%. Thermogravimetric analysis revealed that Pb3O4/PVC nanocomposites have high thermal stability rather than pure PVC film.