INTRODUCTION: Data on the long-term outcomes of Asian patients admitted for acute decompensated heart failure is scarce. The objectives of this study were to determine short-term, intermediate-term and long-term survival among patients admitted for acute decompensated heart failure in Thailand, and to identify factors independently associated with increased mortality. METHODS: Patients who were admitted with a primary diagnosis of heart failure were enrolled in the Thai Acute Decompensated Heart Failure Registry (ADHERE) from 18 hospitals located across Thailand during 2006. Medical record data was collected according to ADHERE protocol. Mortality data was collected from death certificates on file at the Thailand Bureau of Registration Administration. RESULTS: A total of 1,451 patients were included. The mean age of the patients was 63.7 ± 14.4 years, and 49.7% were male. One-year, five-year and ten-year mortality rates in Thai patients admitted for acute decompensated heart failure were 28.0%, 58.2% and 73.3%, respectively. Independent predictors of increased mortality were identified. There were more cardiovascular-related deaths than non-cardiovascular-related deaths (54.6% vs. 45.4%, respectively). CONCLUSIONS The ten-year mortality rate in Thai patients admitted for acute decompensated heart failure was 73.3%. Many factors were found to be independently associated with increased mortality, including left ventricular ejection fraction.