Background :Acute kidney injury(AKI) is common in cirrhosis but differential diagnosis remains a challenge. Serum creatinine (SCr) less sensitive in reflecting renal dysfunction in cirrhotic patients. Aim of the Work: to study the usefulness of NGAL as an early biomarker of AKI in cirrhotic patients. Subjects and Methods: 80 subjects included, classified into 3 groups: GroupΙ: 10 control subjects. Group Π (GpΠ): 40 compensated hepatic patients without AKI, further subdivided into four subcategories: (GpΠa1): 10 patients with HCV under interferon plus ribavirin therapy. (GpΠa2): 10 patients with HCV not under interferon or ribavirin therapy. (GpΠb): 10 patients with Bilharzial liver fibrosis. (GpΠc): 10 patients with combined HCV and Bilharzial liver fibrosis. Group Ш (GpШ): 30 decompensated hepatic patients with AKI, further subdivided into three subcategories: (Gp Шa): 10 patients with Acute tubular necrosis . (Gp Шb): 10 patients with hepatorenal syndrome . (Gp Шc): 10 patients with Pre-renal azotemia. All participants were subjected to the routine lab investigations in addition to specific lab test plasma NGAL (pNGAL).Results: No significant difference was found in kidney function parameters (SCr, urea, GFR) between patients with AKI and patients without AKI. However, patients with AKI had higher pNGAL compared to patients without AKI. There were significant difference among group III subcategories, patients with ATN had pNGAL levels markedly higher (mean 295 ng/ml) compared to those of patients with PRA (mean 86.5 ng/ml), Patients with HRS had intermediate values {mean 142 ng/ml}. In patients with ATN, pNGAL markedly rise within 3 hrs of kidney injury compared to SCr which rises after 24 hrs. Among GpΠ subcategories, no significant difference was found in either pNGAL or kidney function parameters. Conclusions: pNGAL is an early biomarker of AKI and it can also discriminate type of AKI in cirrhosis