OBJECTIVES: Current European Society of Cardiology Guidelines recommend dual antiplatelet therapy for 12 months for patients with acute coronary syndrome (ACS); however, reimbursement for antiplatelet therapy differs by EU country and is dependent upon the use of bare metal (BMS) or drug-eluting (DES) stents during percutaneous coronary intervention (PCI).  Dual antiplatelet (clopidogrel + aspirin) treatment patterns were assessed at 6 months following hospital discharge for patients who received only BMS and for patients with at least 1 DES. METHODS: A prospective, observational registry of 11 European countries grouped into 6 clusters recruited ACS patients undergoing PCI from 2008-2009.  Interventional cardiologists collected data from ACS events up to hospital discharge, and primary care physicians and cardiologists collected 6-month data. RESULTS: Of 3042 eligible patients at baseline, 2964 (97%) had 6-month data, of which 2842 (96%) received a stent at index PCI.  The percentage of patients with at least 1 DES was 17% in the Czech Republic, 31% in Germany, 33% in Austria-Hungary, 33% in Belgium-Netherlands, 37% in the Nordic countries, and 81% in Greece.  The percentage of patients taking dual antiplatelet therapy at hospital discharge ranged from 93% in Belgium-Netherlands to 100% in Greece for BMS only and from 93% in Belgium-Netherlands to 100% in Czech Republic for patients with DES. At 6 months, the percentage of patients taking dual antiplatelet therapy ranged from 45% in Czech Republic to 97% in Greece for BMS-only patients and from 83% in Belgium-Netherlands to 97% in Greece for patients with DES. Aspirin use ranged from 89% to 100% across the countries and type of stent. CONCLUSIONS: Use of DES versus BMS varied among the European countries.  In patients with BMS, there was marked variability with clopidogrel use at 6 months; whereas, in patients with DES, clopidogrel was used more frequently and with less variability.