The optimal duration of clopidogrel administration after percutaneous coronary intervention (PCI) remains unknown. Clopidogrel is currently recommended for minimums of 1 and 12 months after bare-metal stent and drug-eluting stent implantation, respectively. To determine the impact of clopidogrel discontinuation 1 year after PCI, the outcomes of 530 consecutive patients who underwent PCI from January 2004 to July 2006, were free of cardiovascular events for 6 months after PCI, and had follow-up available for >12 months were examined. The outcomes of patients who received clopidogrel for > or =1 year were compared with those of patients who received it for <1 year. The mean age was 65 +/- 9 years. Patients often presented with acute coronary syndromes (57%), and 85% received drug-eluting stents. Clopidogrel was used for > or =1 year and for <1 year in 341 and 189 patients, respectively. During a mean follow-up period of 2.4 +/- 0.8 years, 40 patients (8%) died, 21 (4%) had acute myocardial infarctions, and 89 (17%) underwent repeat coronary revascularization. Compared with patients with clopidogrel administration for <1 year after PCI, those who received clopidogrel for > or =1 year had lower mortality (14.8% vs 3.5%, p <0.001). On multivariate analysis, clopidogrel use for > or =1 year was associated with lower mortality (hazard ratio 0.28, 95% confidence interval 0.14 to 0.59), independent of traditional cardiovascular risk factors, clinical presentation, and the use of drug-eluting stents. In conclusion, the use of clopidogrel for > or =1 year after PCI was associated with lower mortality.