Knowledge of the long-term prognosis (>10 years) and mortality predictors of ST-elevation myocardial infarction (STEMI) patients who have undergone primary percutaneous coronary intervention (p-PCI) is scarce. Therefore, this study evaluated the long-term prognosis and determined the predictors of long-term outcomes for STEMI patients after p-PCI. Between January, 2006 and December, 2010, we collected data and analyzed 459 consecutive patients with acute STEMI who underwent p-PCI and were discharged from the hospital (mean age, 66.8 years; male, 75.2%; peak creatine phosphokinase level, 2,292.5 IU/L). The primary endpoint was 10-year all-cause mortality. The cumulative 10-year incidence of all-cause death was 23.8%. The Cox multivariate regression analysis identified age ≥ 65 years (adjusted hazard ratio [aHR], p <0.001), body mass index (aHR, 0.93, p = 0.033), presence of atrial fibrillation (aHR, 1.69, p = 0.038), mineralocorticoid receptor antagonist use (aHR, 1.95, p = 0.008), ejection fraction <40% (aHR, 2.14, p = 0.005), and albumin <3.5 g/dL (aHR, 2.01, p = 0.005) as independent predictors of all-cause mortality. In conclusion, a post-discharge 10-year survival rate of 76.2% was identified for STEMI patients who underwent p-PCI.