Nanoparticles are particles with dimension on the range 10-9 and 10-10. Green synthesis is the new method developed for the synthesis of nanoparticles which is small in size, large surface area and eco-friendly. In India plant and tree leafs are used as medicine for the treatment of various diseases. They are rich source of antimicrobial agents. Silver, copper and zinc nanoparticles are synthesised from the leaf extract of different plants. Leaf extracts of Glycosmis pentaphylla (Pannal), Macaranga peltata (Vatta), Emilia sonchifolia (Muyal cheviyan), Tabernaemontana divericata (Nandhiar vattam) and Clerodendrum infortunatum (Peravam) are used for the synthesis of nanoparticles. Leaf extract is added to the prepared stock solution of1mM silver nitrate, 100mM copper sulphate and100mM zinc sulphate. Synthesised nanoparticles were characterized by UV-VIS spectrophotometry to confirm the formation of nanoparticles. Anti-bacterial are used to treats bacterial infections. The leaf extract and silver nitrate, copper sulphate, zinc sulphate has antibacterial activity. The antibacterial activity of synthesised nanoparticle is determined using agar well diffusion method. The synthesised nanoparticles exhibit anti- bacterial activity by inhibiting the growth of gram negative and gram positive bacteria.