Abstract Aim : To determine the association of serum, Neutrophil Gelatinase Associated Lipocalin (NGAL) levels and, the need for hemodialysis after a percutaneous coronary intervention (PCI). Design: This is a prospective, observational study. Setting: A cardiovascular and University referral hospital. Patients: Patients with Acute Coronary Syndrome (ACS) that underwent PCI during two consecutive years were enrolled in our study. Main variables of interest: NGAL levels were measured using ELISA. Blood samples were obtained within the first 6 hours of hospital admission, and 12 and 24 hours after contrast exposure from angiography. The primary outcome was the requirement of hemodialysis. The non-parametric Mann-Whitney U test was used to test for differences in median serum levels of NGAL. A receiver operating characteristic (ROC) curve was developed to assess the accuracy of NGAL to predict the need for hemodialysis after PCI. Results : A total of 2,875 were screened; however, 45 patients with ACS that underwent PCI were included. All patients were at high risk of developing Contrast-induced nephropathy (CIN) defined by Mehran score >11 points. The median (IQR) serum concentration of NGAL was significantly higher in patients that required versus did not require hemodialysis (340 [83-384] vs. 169 [100-210], p =0.01). Elevated serum levels of NGAL predicted the need for hemodialysis with an area under the curve of 0.86 (95% CI: 0.66-1.00). Conclusions: In patients with ACS undergoing PCI; and high risk of developing CIN, an elevated serum level of NGAL 6 hours after contrast exposure predicts the development of acute kidney injury requiring hemodialysis.