Heart failure with improved ejection fraction (HFimpEF) represents a nosological entity that has recently been recognized and has little evidence from the literature. Available data indicate an increasing incidence of this patient group, consistent with the progressive improvement and implementation of medical therapy of heart failure with reduced ejection fraction (HFrEF). Furthermore, it is important to underline that the therapy itself should not be suspended after ejection fraction recovery, to avoid the recurrence of worse systolic dysfunction and patient outcomes. Only recently a randomized clinical study has been published, which enrolled also this patient subgroup, the DELIVER trial. Other data will soon become available, given the interest of the scientific community for this subgroup of patients, whose best management remains controversial. Since many studies suggest that the probability of myocardial recovery in HFrEF patients might be as high as 40%, depending on the case series taken into account, whereas the time to recovery might even be 12 months, the appropriate timing of device implantation, such as the defibrillator, in this setting deserves careful consideration.