Background: In cirrhotic individuals, spontaneous bacterial peritonitis (SBP) is a relatively frequent complication. NGAL, or lipocalin linked with neutrophil gelatinase, is a trustworthy indicator of inflammation. Objective: The aim of this work was to evaluate the prognostic value of ascitic neutrophil gelatinase associated lipocalin in decompensated liver cirrhosis with SBP patients. Patients and Methods: The study comprised 72 patients with cirrhotic liver and ascites, they were categorized into two groups SBP group and non SBP group, each group had 36 patients. Each patient had a thorough history-taking process, physical examination, pelvic-abdominal ultrasonography, laboratory tests, and chemical and bacterial analysis of ascitic fluid samples and specific assay of NGAL levels using ELISA technique. Results: We found thatthe optimum cutoff value of NGAL was ≥230.05 ng/ml with (AUC) 0.989, 89.5% positive predictive value, 94.4% specificity, 88.9%, and -94.4% negative predictive value 94.1% and overall accuracy 91.7%. The optimum cutoff of ascitic fluid NGAL in prediction of mortality is ≥401 ng/ml with (AUC) 1, 94.4% overall accuracy, 85.7% of positive predictive value, 100% of negative predictive value, 100% of sensitivity. Conclusion: Ascitic fluid NGAL can be used not only for SBP diagnosis but also for prediction of SBP patients' short-term prognosis. Keywords: