To study synergistic antibacterial activity of zinc oxide nanoparticles incorporated anti bacterial antibiotics against human pathogenic bacteria. Zinc oxide nanoparticles were synthesized by wet method and the synthesized nanoparticles were incorporated ofloxacin, norfloxacin and cephalexin. Anti-bacterial activity was studied against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa adopting agar diffusion assay and biofilm inhibition assay. Zinc oxide nanoparticles were synthesized by wet method showed nanoaggregrates with the size range of 52-75nm.Synthesized nanoparticles with respective antibiotics showed improved anti bacterial activity and the anti bacterial activity of nano drug conjugate against all the tested pathogenic bacteria reveals increase in zone of inhibition and biofilm inhibition as dose dependent manner. The present study would suggests the possible utilization of zinc oxide nanoparticles incorporated antibiotics as an effective anti bacterial agent against pathogenic bacteria.