The book attempts to address, green synthesis of zinc oxide nanoparticles (ZnO NPs) by Phyllanthus emblica, Tinospora cordifolia extracts and its antibacterial activity. In this book a brief introduction have been discussed in the light of different technique used for the synthesis of nanoparticles. At last the book ends by giving data on green synthesis of zinc oxide nanoparticles and the different strategies associated with characterization (UV-Visible spectroscopy, FTIR, SEM, XRD) of nanoparticles and their antimicrobial activity against human pathogenic microorganisms that causes diseases plants and people.