Plant-based green synthesis of nanoparticles has garnered significant attention in contemporary medicine. Specifically, for overcoming opportunistic bacterial pathogens primarily associated with hospital-acquired infections which still face a huge challenge such as Acinetobacter baumannii (A. baumannii) which deaths most burn and intensive care unit patients. Accordingly, green Synthesized TiO2 nanoparticles (TNPs) were prepared from Buckthorn (ZiziphusSpina –Christi) leaves extraction. The produced TNPs were characterized by structural and optical measurements such as Field emission scanning electron microscope (FESEM), the energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and UV-vis spectrometer, the results show homogenous TNPs sizes with decent element distribution for titanium and oxygen. Moreover, the anatase phase of crystallite TNPs was obtained, and the optical band gap of the prepared TNPs was 3.616 eV. Using bacterium isolated from burn patients and utilizing a conventional technique, Vitek 2 compact was employed to identify and test the antibiotic susceptibility of the selective A. baumannii. The antimicrobial activity of green synthesized TNPs against A. baumannii was reported in this study. During the evaluation of extensive-drug resistance A. baumannii with TNPs, various concentrations of TNPs were examined, there was no inhibition region below 25mg/ml, and the minimum inhibition concentration of TNPs was established at 25mg/ml. In this study manufacturing TNPs biologically to combat antibiotic-resistant A. baumannii by using a green method presents a cost-effective and not complicated technique to enhance our lifestyle end reduce the environmental pollution that is produced from traditional chemical or physical nanoparticle synthetization. [ABSTRACT FROM AUTHOR]