All-inorganic cesium lead bromide ( CsPbBr3) perovskite nanoparticles and ZnO nanoparticles were synthesized. The structure, optical properties and the morphology of synthesized nanoparticles were fully characterized using X-ray diffraction (XRD), UV/Vis spectroscopy and transition electron microscopy (TEM). A comparative study was carried out to investigate the antibacterial activity of ZnO and CsPbBr3 perovskite nanoparticles toward Gram-negative, rod-shaped Escherichia coli O157:H7 bacteria cells. Experimental results showed that the antibacterial activity of CsPbBr3 nanoparticles was better than that of ZnO nanoparticles.