Backgrounds: Acute kidney injury (AKI) is a common complication associated with percutaneous coronary intervention (PCI) and independent risk factor for poor long term survival. There has been a paucity of data in terms of long term cardiovascular outcome in patients whether AKI is transient or leads to permanent deterioration of kidney function. The aim of present study is to evaluate long term cardiovascular outcome in transient AKI versus AKI leading to permanent kidney dysfunction. Methods: From January 2004 to December 2009, 7382 patients without history of end stage renal disease or kidney transplantation were selected in COACT (CathOlic medical center percutaneous Coronary intervention) registry. Mean follow up period was 26 months. Patients were stratified according to three categories; no AKI from baseline kidney function, transient AKI with restoration of renal function, AKI leading to persistent kidney dysfunction. Three groups were compared in terms of baseline characteristics, angiographic characteristics. After univariate analysis, multivariate logistic regression was performed for factors associated with persistent renal dysfunction after AKI.Kaplan-Meier curve was constructed to compare clinical outcome of transient AKI and persistent renal dysfunction after AKI. Clinical outcome was evaluated in terms of composite of all cause death, non fatal MI, stroke, target lesion revascularization (TLR), target vessel revascularization (TVR) or by each component. Results: After baseline characteristics and angiographic comparison, transient AKI group showed significantly less frequent renal failure (30.5%, p=0.31), proteinuria (33.5%, p=<0.001), or renal replacement therapy (5.1%, p=0.19) during index admission. Proteinuria on admission, renal failure was significant risk factor for persistent renal dysfunction after AKI. Kaplan-Meier curve shows significantly better composite of all death, stroke, nonfatal MI, TLR, TVR. Conclusion: Transient AKI is better long term prognosis than persistent renal dysfunction after PCI