In this study, we demonstrate a green approach for the synthesis of silver nanoparticles (AgNPs) using aqueous leaf extract of Rosmarinus officinalis under ambient conditions. The uniqueness of this method lies in its rapid synthesis within 15 min. The synthesized AgNPs were characterized using UV-vis, FTIR, XRD, FE-SEM coupled with EDX, TEM and AFM. The synthesized particles were found to be 14.20-42.42 nm with face centered cubic geometry. The functional group of flavonoids and terpenoids was largely identified by MR which was found to be responsible for the synthesis and stabilization of the AgNPs. Further, antibacterial efficacy of the biologically synthesized AgNPs was investigated by the standard method against Pseudomonas aeruginosa and Staphylococcus aureus. The results showed that the aqueous leaf extract mediated synthesized AgNPs is an excellent antibacterial agent against clinical pathogens. (C) 2013 Elsevier Ltd. All rights reserved.