In this study, the comparative investigation of antibacterial activities of Zinc oxide and Silver doped Zinc oxide (Ag-ZnO) towards different strains of bacteria was made. ZnO was prepared by Co-precipitation method while Ag doping was done by green reduction method. For microcrystalline and surface morphological characteristics, samples were introduced to X-ray diffraction and scanning electron microscopy. Extensive growth of hexagonal wurtzite phase of ZnO with crystalline size of 38 nm was observed. On Ag doping crystalline size reduced to 24 nm. Energy dispersive spectroscopy confirms the doping of Ag in ZnO. Disc Diffusion Method was used to investigate antibacterial activity of ZnO and Ag doped ZnO by using Gentamycin as a standard. It was observed that silver doped ZnO showed better antibacterial activity.