Background: Antibiotic resistance is a worldwide problem, associated with increased mortality. Biosynthesized silver nanoparticles are promising solution. Aim: To improve the anti-microbial resistance using Acinetobacter baumannii  (A. baumannii) biosynthesized silver nitrate.Methods: Optimization of biosynthesis condition and characterization by Ultraviolet-Visible spectroscopy (U-V-Vis) at a wavelength from 300 to 400 nm, ±1.67 nm. The Acinetobacter baumannii biosynthesized silver nitrate was examined using transmission electron microscope (TEM).  Fourier transformed infrared spectroscopy was done to study the capping material, X-ray spectroscopy confirm silver nanoparticles synthesis with particle size match TEM measuring and testing its antibacterial effect was done. Results: The obtained U.V Spectroscopy and TEM characters of silver nitrate biosynthesized A.baumannii. Acinetobacter baumannii biosynthesized silver nitrate was obtained indicated. Minimum inhibitory concentration (MIC) was from 1-3 mg/ml against extreme drug resistance bacteria. the size of silver nanoparticles was found to be between 18 nm and 50 nm. The AgNPs were found to be stable for over 6 months at 37°C.The MIC for AgNPs formed from A. baumannii CFF was detected as 2.85 mg/ml, MBC (minimal bactericidal concentration) was 3 mg/ml for K. pneumonia, MIC was 1 mg/ml, MBC was 0.5 mg/ml for P. aeruginosa and MIC was 1.5 mg/ml and MBC was 1 mg/ml for A. baumannii isolates. Lethal concentration (LC) 50% was 60.584 ug/ml) assessed by Sulforhodamine-B assay on hepatocellular carcinoma cell line. Conclusion: Acinetobacter baumannii extracted silver nitrate has A promising antibacterial action that may help in solving the multidrug resistance bacteria.