Acute kidney injury (AKI) is largely asymptomatic, and establishing the diagnosis in thisin creasingly common disorder currently hinges on functional biomarkers such as serum creatinine. Early neutrophil gelatinase-associated lipocalin (NGAL) measurements can identify patients with sub-clinical AKI who have an increased risk of adverse outcomes, even in the absence of diagnostic increases in serum creatinine. NGAL is emerging as an excellent biomarker in the urine and plasma, for the early prediction of AKI, for monitoring clinical trials in AKI, and for the prognosis of AKI in several common clinical scenarios. Also numerous studies have also demonstrated that NGAL may be a potential biomarker for the diagnosis, prediction, prevention, and prognosis of non-AKI diseases such as chronic kidney diseases, vascular disorders, cancer, preeclampsia, and allergies. The current status of the most promising of novel biomarkers in medicin as NGAL is appraised in this review.