The study reports a one-step preparation of polyvinyl alcohol/boiled rice starch blend film fabricated with in situ generated silver nanoparticles (PVA/BRS/sAgNPs) formed in the presence of sunlight irradiation. The bionanocomposite appeared to have dark brown color with a characteristic surface plasmon resonance peak at 439 nm. Further characterization has confirmed the presence of physical interactions among the components PVA, BRS and sAgNPs. Compared to the control PVA, the nanocomposites showed improved mechanical and optical properties with decreased water sensitivity. Presence of boiled rice starch and sAgNPs were also found to influence the light transmittance of composite film. Moreover, PVA/BRS/sAgNPs film was found to have superior barrier property against environmental microorganisms. Biodegradation of the composite films was studied by indoor soil burial test and was assessed by visual appearance, weight loss and FTIR analysis. Interestingly, both the PVA/BRS and PVA/BRS/sAgNPs films proved to be biodegradable and hence have promising application as cost effective food packaging material with the latter having marked antimicrobial property.