Purpose: Veno-Arterial Extracorporeal Membrane Oxygenation (VA-ECMO) has been reported to improve survival in patients with cardiogenic shock or cardiac arrest. We investigated the association between initial renal function just before implantation and clinical outcome in patients undergoing VA-ECMO due to cardiogenic shock and cardiac arrest. Methods: A cohort of 212 patients (58.8±16.2 years old, 86% male) who underwent ECMO at our hospital was registered from January 2007 to December 2013. We excluded 68 patients caused by non-cardiogenic event. The remaining 144 patients (91 with acute myocardial infarction, 37 with refractory ventricular fibrillation, 6 with refractory congestive heart failure, and 6 with fulminant myocarditis) were divided into 2 groups according to initial estimated-glomerular filtration rate (eGFR). Non-CKD Group: eGFR ≥60ml/min/1.73m 2 (n=98); CKD Group: eGFR <60 (n=46). Clinical outcome was defined as all-cause death at discharge. Results: The 82% of patients received VA-ECMO due to cardiac arrest. In baseline characteristics, Non-CKD group was significantly younger (50.4 vs. 62.8 years old), lower incidence of hypertension in past history (26.1 vs.52.0 %), lower BUN (13.7 vs. 24.3 mg/dl), and lower K (3.9 vs. 4.5 mEq/l, all p<0.05) than CKD group. Incidence of all-cause death was significantly lower in Non-CKD group than in CKD group (Non-CKD vs. CKD: 60.9% vs. 78.6%: p=0.026) (Figure). The low eGFR was an independent predictor of mortality after adjustment of multiple cofounders (eGFR <60, OR: 2.87, 95% confidence interval: 1.04-7.94, p=0.042). Negative independent predictors of mortality were fulminant myocarditis (OR: 0.08, 95% CI: 0.007-0.99, p=0.049) and count of platelet (per increase, OR: 0.94, 95% confidence interval: 0.88-0.99, p=0.037) Conclusion: Initial low e-GFR just before implantation provides worse clinical outcome in patients with VA-ECMO due to cardiogenic shock and cardiac arrest.