The length of hospital stay after a successful percutaneous coronary intervention (PCI) for acute myocardial infarction is subject of debate. Patients should not be kept in hospital longer than strictly needed in terms of safety, psycho-social reasons, adequate mobilisation and patient comfort. In many tertiary centres with a busy PCI program insufficient bed capacity is an ongoing concern. Moreover, it seems obvious that shorter hospital stay will lead to a significant cost reduction. In order to know if very early discharge after primary PCI is feasible and safe one should identify the events that might threaten the patient as well as the timing of occurrence of such events. As a result a relatively large proportion of patients with a very low risk of early complications can be defined and in those patients very early discharge is indicated.