Pure and Zn doped CuO nanoparticles have been synthesized by co-precipitation method. Structural characterization reveals that the prepared materials are in monoclinic structure. Band gap value of the calculated from optical spectrum and it is observed band gap of the prepared materials gets decrease by increasing the concentration of dopant. It is evidently visible in SEM picture that the Zn doped CuO nanoparticles are nearly globular in form with identical size distribution. Antibacterial activity of the title materials have also been tested against Acinetobacterbaumanni and Klebsiella pneumonia.