Global efforts to reduce hazardous wastes and alarming environmental issues urge the need to develop more and more ecofriendly processes and bio-compatible products. In this study, silver nano particles were synthesized using stingless bee propolis (Tetragonula iridipennis) reared from Tamilnadu. The bio-reduction process was further intensified by ultrasonics irradiation. The synthesized silver nano particles were well characterized by UVvisible spectrophotometer, Energy dispersive X-ray analysis, Scanning electron Microscope, Dynamic light scattering measurement. The active functional groups were identified by Fourier Transform Infra-red spectroscopy. The crystalline nature was established by XRD technique. The anticancer potential of the synthesized silver nano particles was evaluated by MTT assay and it was found to show significant activity against A549 human lung cancer cells. IC 50 value is 38 μg/ml.