Heart failure (HF) results in substantial morbidity, mortality, and costs, yet quality of care varies widely and is frequently inadequate. Performance improvement registries have been developed to improve the quality of care and outcomes for patients with HF in both the inpatient and outpatient settings. HF registries in the United States include ADHERE, OPTIMIZE-HF, GWTG-HF, and IMPROVE HF. These registries collect data on clinical characteristics, admission, hospital, discharge, and/or outpatient care, as well as outcomes. Web-based tools that provide real-time feedback of performance and other quality measures benchmarked to other sites and national data are frequently utilized. Process-of-care improvement tools, including evidence-based clinical decision support, customizable order sets, and patient education are also used. Participation in performance improvement registries has been associated with substantial improvements in the use of guideline-recommended therapies for HF in both the inpatient and outpatient settings. Conformity with HF quality measures has also been shown to improve and disparities in care have also been reduced or eliminated. There have also been improvements in clinical outcomes. This paper reviews the evidence that participation in HF performance improvement registries is associated with improved use of guideline-recommended HF therapies, better conformity with quality measures, and improved outcomes in patients with HF. (Circ J 2011; 75: 1783-1790)