Nearly half of patients with symptoms of heart failure are found to have a normal left ventricular (LV) ejection fraction. This has variously been labelled as diastolic heart failure, heart failure with preserved LV function or heart failure with a normal ejection fraction (HFNEF). As recent studies have shown that systolic function is not entirely normal in these patients, HFNEF is the preferred term. The epidemiology, aetiology and possible pathophysiology of this contentious condition are reviewed. The importance of the remodelling process in determining whether a patient presents with systolic heart failure or HFNEF is emphasised and this can be used to classify patients in a more rational manner.