Background: The ability to rapidly identify patients with ST-segment elevation-myocardial infarction (STEMI) at hospitals without percutaneous coronary intervention (PCI) capability and transfer them to hospitals with PCI capability is critical to STEMI. The aim of this study was to evaluate the relationship between clinical outcomes and transfer to hospitals with PCI capability in STEMI and non-STEMI patients. Methods: We evaluated 3,576 STEMI patients who admitted within 12 hours of symptom onset and with door-to-balloon time ���6 hours) and 2,731 non-STEMI patients within 1 week of symptom onset and with PCI done within 2 weeks after presentation. The primary outcome was the composite of major adverse clinical event (MACE), defined as death, non-fatal MI, or revascularization. Results: In STEMI, symptom onset-to-door time was significantly shorter in on-site PCI group than in PCI after inter-hospital transfer group (144 vs. 233 min, p<0.001), but symptom onset –to-first medical contact time was significantly longer in on-site PCI group than PCI after inter-hospital transfer group (135 vs. 114 min, p<0.001). Door-to-balloon time was shorter in PCI after inter-hospital transfer group. This pattern was similar in non-STEMI. In STEMI, there was no significant difference between two groups regarding in-hospital, 1, 6, and 12 month composite of MACE. Similar pattern was seen in non-STEMI. Conclusions: Transfer to hospitals with PCI capability with modest increase of ischemia time did not affect clinical outcomes in MI patients. This study suggests that inter-hospital transfer should be encouraged in the area of geographic accessibility similar to Korea.