10.22376/ijpbs.2019.10.1.p1-12 Volume 3 Issue 2 2012 (April - June) The silver nanoparticles (AgNPs) synthesized using aqueous leaf extract of lessThan i greaterThan Lepisanthes tetraphylla lessThan /i greaterThan  as the reducing agent were evaluated for antibacterial activity against drug resistant bacterial isolates. The nature of AgNPs synthesized were analysed by UV-Vis spectroscopy, X-ray diffraction and Scanning electron microscopy. The silver nanoparticles were with an average size of 30nm, spherical and poly-dispersed. The antibacterial potential of synthesized AgNPs were compared with that of crude methanolic leaf extract of Lepisanthes tetraphylla by well diffusion method. The AgNPs at 30-50µg(0.03-0.05mg) concentration significantly inhibited bacterial growth against multi drug resistant lessThan i greaterThan Staphylococcus aureus lessThan /i greaterThan , lessThan i greaterThan Escherichia coli lessThan /i greaterThan , lessThan i greaterThan Pseudomonas aeruginosa and Acinetobacter species lessThan /i greaterThan . The study revealed that crude methanolic leaf extract of L.tetraphylla inhibited the growth of only lessThan i greaterThan Escherichia coli lessThan /i greaterThan , at 1mg/ml concentration. Thus AgNPs showed broad spectrum antibacterial activity at lower concentration may be a good alternative therapeutic approach in future. N.Meena, M.Jeya, S.Aroumugame, P.Arumugam And E.Sagadevan Lepisanthes tetraphylla, antibacterial activity, silver nanoparticles, well diffusion method 593-601