Clinical nephrology is discovering neutrophil gelatinase-associated lipocalin (NGAL), a small 25-kDa protein belonging to the lipocalin family, as one of the most promising biomarkers in the diagnostic field of acute kidney injury also suggesting NGAL production from tubular cells may reflect the entity of active renal damage that underlies the chronic impairment condition. In this study, we are aiming to highlight the role of NGAL in assessment the severity of renal impairment. For this reason serum-NGAL and urinary-NGAL was evaluated in a cohort of chronic kidney diseased patients with special consideration to different stages of chronic renal impairment in order to verify the relationship with the severity of renal impairment. Our results showed that in CKD patients' serum-NGAL, urinary-NGAL and the fractional excretion of this protein were notably increased as compared to controls and there was a statistical significant variation with each stage of chronic renal impairment.