Quality improvement in cardiac care has made considerable progress over the past 30 years. During that period, there has been the development of multi-institutional databases to monitor outcomes following cardiothoracic surgery. These databases initially began using only volume and unadjusted operative (30-day) mortality as outcome criteria. There has been a progressive increase in their sophistication, with the building of risk models based on preoperative variables, which accurately predict the risk of adverse outcomes. Other outcomes have been added including risk-adjusted mortality and morbidity; efficiency outcomes such as length of stay, quality of life, functional health status, neuropsychological outcomes; and long-term outcomes.