Although numerous scores have been designed to provide stratification of morbidity and mortality outcome by preoperative risk factors and to determine patients at risk from prolonged length of ICU and hospital stay after cardiac surgery, the predictive power of these scores for individual prognosis remains poor. However, scoring in cardiac surgery may be used for a different purpose. With increasing health care costs fast-track intensive care treatment saving ICU resources has become an important issue in cardiac surgery. With the help of scoring systems that can accurately identify low-risk patients who will have a favourable postoperative course a subset of patients eligible for early ward referral can be defined. Thus, scoring may save total ICU days of cardiac surgical patients and reduce costs.