The epidemiology and clinical characteristics of acute decompensated heart failure (ADHF) and the management of patients with ADHF are discussed. ADHF has become a significant health care problem in the United States. In an effort to fully understand the current epidemiology, clinical characteristics, and management of patients hospitalized with ADHF, a national registry was started in 2002 as a joint collaboration between academic heart failure specialists and the bio-pharmaceutical industry. The largest compilation of ADHF data has been collected in the Acute Decompensated Heart Failure National Registry (ADHERE). This article describes ADHERE, which suggests that the health care industry needs to conduct root-cause analysis of outpatient and inpatient practices toward these patients and make adjustments in these treatment patterns if we are going to reduce the morbidity, mortality, and health care costs in these patients.