Contrast-induced acute kidney injury (CI-AKI) is associated with increased mortality, morbidity, and prolonged hospitalization. Patients with acute coronary syndrome (ACS) have a 3-fold higher risk of developing CI-AKI. The aim of our study was to evaluate the predictors of CI-AKI and long-term prognosis in patients with ACS who developed CI-AKI (1083 patients were enrolled). Contrast-induced acute kidney injury was defined as an increase of 0.5 mg/dL and/or an increase of 25% of pre-percutaneous coronary intervention (PCI) to post-PCI serum creatinine levels within 48 to 72 hours after the procedure. Primary end point was defined as all-cause mortality, myocardial infarction, and cerebrovascular event at long-term follow-up (36 +/- 12 months). Contrast-induced acute kidney injury occurred in 178 (16.4%) of the 1083 patients. The primary end points were significantly high in patients with ACS who developed CI-AKI (P < .001). The occurrence of CI-AKI was identified as an independent predictor of primary end point. Risk of CI-AKI development was more frequently seen in patients with ACS. Also, patients who developed CI-AKI have worse prognosis at long-term follow-up. Additional preventive treatment strategies need to be developed in this group of patients.