Background竊� There are very limited data regarding the influences of previous myocardial infarction (MI) on the outcomes of recurrent acute non-ST-segment elevation MI (re-NSTEMI) patients (pts), especially after primary percutaneous coronary intervention (PCI) in DES era. Method: The current data came from the Korea Acute Myocardial Infarction Registry (KAMIR) study, which consisted of 4121 consecutive acute NSTEMI pts enrolled from November 2005 to April 2008. Among them, 492 (11.94%) pts presented with recurrent AMI (NSTEMI) with previous history of MI. We compared the clinical outcomes of re-AMI pts presented as NSTEMI with those of first-onset NSTEMI (first-AMI group, n=3629) at 12 months. Results: The baseline characteristics are largely unfavorable in re-MI group over first-AMI group. At 12 months, although the incidence of repeat PCI were similar between the groups, the mortality, recurrent AMI (primarily due to increased NSTEMI), and major adverse cardiac events (MACE) were higher in the re-AMI group compared with those of first-AMI group (Table). Previous MI was an independent predictor of MACE at 12 months in re-AMI group (ORunadjusted:1.771, 95% CI: 1.378-2.276, P<0.001) even after adjusted of many confounding variables (ORadjusted:1.503, 95% CI: 1.084-2.086, P=0.015). Conclusion: Acute NSTEMI pts with previous MI presented with worse baseline clinical and procedural characteristics and more associated with worse major clinical outcomes up to 12 months compared with those of first onset NSTEMI pts.