Backgrounds: Percutaneous coronary intervention (PCI) is often complicated by acute kidney injury (AKI) and resulting in permanent renal dysfunction or restoration of normal renal function. However factors associated with clinical course of AKI is not well known. The aim of the present study is to investigate factors which predicts the clinical course of AKI whether to transient renal injury or permanent renal dysfunction. Methods: From January 2004 to December 2009, 7382 patients without history of end stage renal disease or kidney transplantation were selected frm COACT ( CathOlic medical center percutaneous Coronary intervention) registry. Mean follow up period was 26 months. 474 patients diagnosed with acute kidney injury after PCI were selected and stratified into two categories; AKI with transient renal dysfunction within 12 weeks (transient AKI), and AKI leading to persistent renal dysfunction(persistent kidney injury). The definition of AKI is according to the Acute Kidney Injury Network criteria. After comparison of baseline characteristics, univariate and multivariate logistic analysis was performed to evaluate factors predicting either transient AKI or persistent kidney injury. Results: Baseline characteristic analysis revealed that diagnosed CKD (p= 0.034), presence of proteinuria(p < 0.001), renal replacement during index admission (p= 0.002) were significantly different between both groups. Gender, hypertension, diabetes, hemoglobin or ejection fraction is not significantly different. After multivariate analysis, proteinuria (HR= 3.717, 95% CI: 1.438-9.609), eGFR <60 mg/dl (HR= 2.68, 95% CI: 1.002-7.17) Conclusion: Proteinuria and eGFR < 60 mg/dl is significant predictors of persistent renal dysfunction after AKI