Neutrophil gelatinase associated lipocalin (NGAL) is a 25 kDa protein of the lipocalin family. This article's goal is to investigate the role of serum NGAL in kidney illnesses such as acute kidney injury and chronic renal failure, as well as how aging affects NGAL levels. Participants (n=300) in the present study were classified into 3 groups. Group I: Normal healthy control participants (n=100). Group II: Acute kidney damage (AKI) patients (n==100). Group III: Chronic renal failure (CRF) patients (n=100). Those groups further divided into subgroups based on age and gender. Blood samples were collected from patients for laboratory investigation as blood urea, serum creatinine, sodium, potassium, blood Hb, GFR, pH, PCO2 and serum NGAL. Demonstrate that regardless of gender, the levels of serum NGAL were considerably more significant in patients with CRF than in those with AKI, and that the levels of NGAL are correlated with age. The levels of NGAL in CRF and AKI of males groups were (462 ±31.9, 652 ± 83) and (330 ± 45.30, 534 ± 61.1) ng/ ml respectively and in females groups were (668 ± 68.3, 730 ± 75.5) and (380 ±70.4, 466 ± 48.8) ng/ml respectively. Conclusions: Serum NGAL may be a valid marker to differentiate between AKI and CRF patients and its level is influenced by age.