Plant based biosynthesis of metal nanoparticles has proved to be an effective and novel method of synthesis. Various parts of plants have been investigated for the synthesis of metal nanoparticles. In our present work we present the synthesis of metal nanoparticles using the extract taken from the leaves such as Sesbania grandiflora (Agati), Morinda Citrifolia (Noni) and Tectona Grandis (Teak). The silver nanoparticles synthesized were spherical in shape of around 100 nm size and showed good results against the microorganisms such as Staphylococcus aureus and Pseudomonas aeruginosa.Their effect on microorganisms was compared with that of the antibiotics such as Vancomycin, Fluconazole, Tetracycline, Amikacin, Ceftazidime etc. The Silver nanoparticles synthesised by this method showed comparable effect, in case of Pseudomonas aeruginosa, with that of Amikacin which is used as a last-resort medication against multidrug-resistant bacteria.