Background: Acute decompensated heart failure (ADHF) patients experience high rates of hospital stays and mortality. Predictors of in-hospital mortality have not been identified and there have not been any heart failure (HF)registries in asian population. The purpose of this study was to develop a clinical predictors of in-hospital mortality in hospitalized ADHF patients in Korea. Methods: The KorHF(Korean Heart Failure) Registry is a registry for patients who hospitalized with ADHF in Korean hospitals. All significant variables (p<0.05) were entered into multivariate analysis. Nineteen predictor variables were entered into chi-square analysis for in-hospital mortality. All significant variables were entered into a logistic regression analysis for in-hospital mortality. Results: Of 3,200 patients enrolled, mean age was 67.58 짹 1.43 years, 50% were men, and 37% had ischemic heart diseases(IHD). In-hospital mortality occurred in 276 (7.1%). Multivariable predictors of mortality included serum sodium level, the use of angiotensin-converting enzyme inhibitor (ACEI) or beta-blocker, history of ischemic heart disease as the cause of HF, New York Heart Association(NYHA) functional class. All significant variables were listed on the table. Conclusions: Risk of in-hospital mortality for patients hospitalized with ADHF remains high and was increased in patients who have lower sodium levels, higher NYHA functional class, history of ischemic heart disease as the cause of HF, and did not use of ACEI and beta-bloker at the time of admission . Application of this risk-predictictor might help identify patients at high risk for in-hospital mortality who might benefit from aggressive monitoring and intervention in asian population