Ischaemic heart disease is becoming an increasingly frequent cause of ischaemic mitral regurgitation (IMR). Three different clinical entities of IMR, which deeply affect the clinical decision making, are distinguishable: the acute IMR complicating an acute myocardial infarction, the true IMR secondary to a transient ischaemic phenomenon, and the chronic functional IMR (FIMR). The incidence of the two first entities is low; the third is much more frequent.