Background : The role of primary transradial PCI for acute myocardial infaction (AMI) has not been established well. We sought to evaluate the safety and efficacy of transradial compared to transfemoral approach for the patients with AMI. Methods : From March 1988 to December 2002, two hundred patients (100 for transradial, 100 for transfemoral group, mean age, 59짹9) were enrolled prospectively in the setting of primary percutaneous coronary intervention (PCI) for the patients within 12 hours from onset of AMI. Transradial approach were allowed when the patients were hemodynamically stable and had good radial pulse. Results : Culprit vessels were LAD of 57(48), RCA of 36(40), LCX of 5(10) and LMT 2(2) in radial(femoral) group. Total procedure time and perfusion time (time from catheterization room to culprit vessel perfusion) were not different between two groups (45짹18 vs 51짹25 and 22짹7 vs 24짹9 minutes, radial vs femoral). Three patients of radial group had been changed to the femoral approach due to puncture failure and one of femoral group had been changed to the radial approach due to femoral artery occlusion. In-hospital major adverse cardiac event were 2 in radial group and 5 in femoral group. Conclusions : Transradial primary PCI is safe and useful alternative approach without procedure time increament in the setting of hemodynamically stable AMI patients.