Infectious diseases are caused by pathogens, such as viruses, bacteria, fungi, and parasites. Quinolones work by inhibition of bacterial topoisomerase IV and/or gyrase, a group of oxadiazole derivatives were incorporated into C7 piperazine ring of Gatifloxacin, a well-known antibacterial fluoroquinolone, in order to increase bulkiness at C7 leading to reduce bacterial resistance and improve anti-bacterial activity. In the current work , the synthesized compounds V(a-e) were screened for their antibacterial activity against gram negative bacteria: Klebsiella pneumonia and Escherichia coli and gram positive bacteria Streptococcus pyougenes and Staphylococcus aureus bacteria, the tested compounds showed an interesting activity against gram positive and gram negative bacteria, these tested compounds give significant antibacterial activity in comparison to Gatifloxacin as a starting compound and DMSO as a control, confirmations and characterization of the chemical structures related to these compounds were performed using 1H-NMR spectroscopy, FT-IR spectroscopy, and some physicochemical properties such as melting points. Docking study of the final synthesized compounds gave evidence about the affinity of these compounds toward topoisomerase IV enzyme, statistical results show the elevated inhibitory zones of the prepared compounds compared with Gatifloxacin, regarding S. aureus bacteria the inhibition zone elevated from 18mm in Gatifloxacin to 24 in (Vb and Ve) and 26mm in Vd, also for K. pneumonia bacteria the zone of inhibition raised from 18mm in Gatifloxacin to 20mm in Vb and 24mm in Ve.