Background: Epidemiologic studies describes gender differences of clinical features and treatment patterns in ST-segment elevated acute myocardial infarction (STEMI). We therefore analyzed a database from a nationwide, prospective, multicenter, KORean acute Myocardial Infarction resistry (KORMI) study of AMI, to access the difference of clinical features and treatment patterns in men and women. Method and Results: Between January 2008 to July 2008, 1111 patients who admitted with STEMI were registered to KORMI database. Of these patients, 283 (26%) were women and 828 (74%) were men. Compared with men, women were 12 years older in average than men (p<0.001) and had higher incidence of hypertension (77.3 vs 66.5%, p=0.01) and metabolic syndrome (78.4 vs 62.0%, p<0.001). Although the incidence of LVEF<40% was similar (16.2 vs 15.6%, p=NS), Killip class ��� 2 was higher (34.6 vs 23.6%, p=0.001) in women then men. Women were more likely than men to have atypical symptoms (13.1 vs 9.5%, p<0.001) and had dyspnea (29.3 vs 21.6, p=0.013). The time interval from chest pain to medical contact time was longer and the incidence of ER arrival <12 hrs after symptom onset was lower in women. On treatment, the rate of reperfusion therapy <12hrs after chest pain were similar in both. In-hospital mortality was similar (Table). Conclusions: In this study, women with STEMI have contacted medical facilities delayed than men, but in-hospital treatment patterns were similar. Recent active in-hospital treatment abolished inferior outcomes of delayed medical contact in female patients.