Background: Tirofiban is alternative to abciximab offering anti-platelet effect at a lower cost. However the early use of tirofiban on the primary infarct related artery stenting in acute myocardial infarction(AMI) has not yet been defined. Objectives: This study examined the efficacy and safety of tirofiban as adjunctive therapy to infarct related artery stenting. Methods: Patients(N=192) with a first ST elevated myocardial infarction within 6 hours from onset of symptoms were undergo infarct related artery stenting alone(N=95) or tirofiban plus stenting(N=97). The primary end point was recovery of TIMI 3 flow after stenting. Secondary end points were composite end point at 30 days (death, reinfartion, revascularization procedures, stroke), and major bleeding complication. Results: Primary stenting alone group achieved 83.2% of TIMI 3 flow compared with 89.7% when tirofiban was used (p=0.03). The incidence of secondary end points were 13.7% and 9.3% in stenting alone and stenting plus tirofiban group, respectively(p=0.34). The rate of major bleeding was similar for stenting alone versus regimen with tirofiban (2.1% vs. 3.0% p=0.66). Conclusion: The adjunctive use of tirofiban is safe and achived higher rate of TIMI 3 flow. Tirofiban plus infarct related artery stenting should be considered in patients with AMI undergoing primary stenting