Ejection fraction (EF) reflects both cardiac function and remodeling, and is widely recognized as a valuable diagnostic and prognostic tool. Its use in a variety of settings, ranging from heart failure and myocardial infarction to valvular heart disease, has made it a cornerstone of modern cardiology, pervading guidelines and practice. However, the development of the test was in another era, with younger patients and a lower prevalence of heart failure with preserved EF. The performance expectations of EF in the current era are also demanding-in relation to detection of subclinical LV dysfunction, and especially relating to recognition of changes in LV function on sequential testing-for example in patients taking cardiotoxic drugs. This review discusses whether the impressive evidence base for EF justifies its ongoing use in the context of newer markers of LV function, and the sophisticated questions posed by modern cardiology.