Nanoparticles obtained from physical and chemical methods are uniformly sized having long term stabilities. However, their syntheses usually involve expensive chemicals which are toxic, carcinogenic and require high temperature and pressure. These issues can be addressed by facile and eco-friendly green synthesis. This study focuses on to synthesis of zinc oxide nanoparticles (ZnO NPs) using Cymbogobon Citratus aqueous extract with zinc acetate. The prepared particles were calcined at 450oC. The synthesized NPs were categorized using FTIR, UV-Visible, XRD and SEM techniques. FTIR verified zinc oxide vibrational frequency at 551 cm^-1. UV-Visible spectrum displayed the ZnO absorption peak at λ_max of 370 nm. XRD studies showed average particle size about 4.96 nm much smaller as compared to most of the ZnO NPs reported earlier. SEM image demonstrated crystalline and porous nano-sheets for the prepared NPs. These NPs were also evaluated against Staphylococcus aureus, Escherichia coli, Salmonella typhi, Microsporum cannis, Aspergillus flavus and Fusarium solani. The synthesized ZnO NPs exhibited highest antibacterial and antifungal potential against S. Aureus and A. flavus, respectively.