Background: Bleeding has recently emerged as a predictor of early and late mortality after percutaneous coronary intervention (PCI). Full anticoagulation and multiple antiplatelets increase the risk of post-PCI bleeding in acute myocardial infarction (AMI). Radial access (RA) reduces bleeding and vascular complications compared with femoral access (FA). We investigated the association of vascular access site with in-hospital and one-year clinical outcomes in patients with AMI who underwent PCI. Methods: A total of 13,865 patients from the Korea Acute Myocardial Infarction Registry were evaluated according to FA or RA. The primary outcome was the composite of in-hospital major adverse cardiac events including death, non-fatal myocardial infarction, and revascularization. Results: PCIs were undergone using FA in 11,427(82.4%) patients and RA in 2,438(17.6%). RA group was younger, more male and had lower Killip class and lower frequency of concomitant medical illness. The primary outcome was higher in FA group than RA group (7.0% vs. 2.6%, p<0.0001). This difference has been sustained by one-year (15.1% vs. 8.3%, p<0.0001). However, in-hospital major bleeding was similar (0.4% vs. 0.3%). In multivariable analysis, major bleeding and RA were predictors of in-hospital mortality (OR 7.80, 95% CI 3.14-19.40, p<0.0001; OR 0.29, 95% CI 0.14-0.58, p=0.0005, respectively) and one-year mortality (OR 5.52, 95% CI 2.40-12.69, p<0.0001; OR 0.45, 95% CI 0.30-0.67, p<0.0001, respectively). In propensity-matched analysis, RA remained predictor of in-hospital and one-year mortality (OR 0.10, 95% CI 0.01-0.77, p=0.0274; OR 0.47, 95% CI 0.23-0.97, p=0.0415, respectively). Conclusion: In real-world AMI patients who underwent PCI, RA was associated with more favorable in-hospital and one-year outcomes compared with FA.