This study was aimed to synthesize the Zinc oxide nanoparticles (ZnONPs) and to investigate its antibacterial activity against different bacteria. NP was synthesized by water medium method. The characterization of nanoparticles (NPs) was done by XRD and FTIR method. Antibacterial activity was investigated by disc diffusion and well diffusion method. It was found that synthesized ZnONPs showed antibacterial activity in the form of zone of inhibition. Zinc oxide nanoparticles (ZnONPs) dissolved in three different solvent like water, N-Hexane, 70% Ethanol. All three different solvent with Zinc oxide nanoparticles showed the zone of inhibition against bacteria studied - E.coli, S.typhi and S.aureus. Maximum zone of inhibition was observed in 0.5 gm con. of ZnONPs in 70% ethanol against S.typhi. Minimum zone of inhibition was observed in 0.1 gm con. of ZnONPs in water against E.coli and S.arureus. Zone of inhibition was observed increased with increase in concentration of ZnONPs. Results of present study may be use in the development of antibiotic treatment against different bacterial infections.