Data of long-term efficacy and safety including bleeding risk associated with antithrombotic regimens after primary percutaneous coronary intervention (PCI) using first-generation drug-eluting stent (1st DES) are scarce. Consecutive 422 patients with ST-elevation myocardial infarction (STEMI) underwent primary PCI with DES (285 patients), bare metal stent (BMS, 58 patients) or balloon angioplasty (BA 79 patients). At a median follow-up of 44 months, major cardiovascular events were significantly lower for 1st DES compared with BMS and BA (11.9 vs. 25.9 vs. 16.5 %, p = 0.027). Cardiac death, recurrent myocardial infarction and target lesion revascularization (TLR), differed among the groups (DES 8.8 %; BMS 13.8 %; BA 17.7 %; p = 0.019), although the superiority of DES subsided beyond 1 year by increased late TLRs. Major bleedings were not higher in DES than in BMS and BA (4.6 vs. 6.9 vs. 1.5 %, p = 0.252). Multivariate logistic regression analysis revealed that both dual antiplatelet therapy (DAPT) >24 months and indefinite oral anticoagulation (OAC) were associated with a major bleeding. The risk was even greater with triple antithrombotic therapy (odds ratio 19.5; 95 % confidence interval 3.73-102.07; p < 0.0001). 1st DES showed favorable overall long-term clinical outcome in STEMI, with an inherent limitation of an increased risk of late TLR. Prolonged DAPT and OAC synergistically increase the risk of major bleeding after primary PCI.