Background : Ischemic and non-ischemic cardiomyopathy (ICM and NICM) both cause heart failure, but the different etiologies may result in differences in management and outcome. Methods : We analyzed 1,407 patients with ICM and 654 patients with NICM from the Korean Acute Heart Failure (KorHF) Registry, which conducted from November 2005 to November 2009 from 24 university hospitals in Korea. Results : Patients with ICM were older than NICM (70짹12 vs 63짹16 years, p<0.001). QRS duration was shorter and corrected QT interval was longer in patients with ICM. Serum levels of BUN, creatinine, glucose, total cholesterol, potassium, C-reactive protein and N-terminal pronatriuretic peptide were higher in patients with ICM. Left ventricular ejection fraction and deceleration time of early filling mitral inflow were lower in patients with NICM. Infusion of dopamine, mechanical ventrilatory support and intra-aortic balloon counterpulsation in initial treatment were used more frequently in patients with ICM. Use of angiotensin receptor blocker and spironolactone were higher, and use and dosage of beta-blocker were lower in patients with NICM. One year mortality and rehospitalization were higher in patients with ICM by Kaplan-Meier survival curve analysis (p<0.001 by Log Rank analysis). Conclusion : Clinical characteristics and management of heart failure were different according to etiologies of heart failure. Mortality of patients with cardiomyopathy remains high and patients with ICM had poorer prognosis than patients with NICM.