A series of Zinc Oxide Nanoparticles (ZnONPs)-functionalized Multi-Walled Carbon Nanotubes (F-MWCNTs) Nano composites were developed as antibacterial. In this study, chemical oxidation of pristine MWCNTs were carried out with a mixture of strong acids (3H2SO4 98%:1 HNO3 65%).The F-MWCNTs were used as templates to prepare hybrid material like ZnONPs decorated F-MWCNTs. Pristine MWCNTs, F-MWCNTs and (ZnONPs/F-MWCNTs) Nano composites powder were investigated using Fourier Transform Infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Anti-bacterial activity has been carried out using standard agar dilution (plate count) method against Escherichia coli (E. coli). This study demonstrated that (ZnONPs/F-MWCNTs) Nano composite has a powerful bactericidal effect against Escherichia coli (E. coli) at concentration 0.5 mg/ml after 3 hr, which led to speculation that the combination of ZnONPs and F-MWCNTs altered their toxicity and improved antibacterial property of Nano composite.