Stable silver nanoparticles were synthesized from AgNO3 through a simple green route using biodegradable and renewable starch as stabilizing agent. Nanoparticles have been studied for their formation, structure, morphology and size using UV–vis spectroscopy, X-ray diffraction (XRD) and HRTEM analysis. XRD showed that the nanoparticles were of face centered cubic structure. UV–Vis and HRTEM revealed that the spherical particles having radius 5-20 nm are mostly stabilized by starch. Further, antibacterial properties of these starch-stabilized nanoparticles show promising results for S.aureus in growth inhibition ring test.