The impact of the CYP2C19*17 polymorphism on the clinical outcome in Asians undergoing percutaneous coronary intervention (PCI) is unknown. We sought to assess the long-term impact of CYP2C19*17 on the risk for adverse clinical events in 2188 Korean patients taking clopidogrel after PCI. The prevalence of the CYP2C19*17 allele [*wt/*17: 2.4% (n = 53), *17/*17: 0%] was very low. The 2-year cumulative event rates for bleeding [*wt/*17 vs. *wt/*wt: 2 vs. 2.3%; adjusted hazard ratio (HR), 1.23; 95% confidence interval (CI), 0.16-9.45], stent thrombosis (2 vs. 1.1%; HR, 3.98; 95% CI, 0.49-31.6) or composite of any death, and myocardial infarction or stroke (5.4 vs. 7.1%; HR, 1.37; 95% CI, 0.32-5.73) did not differ on the basis of the presence of CYP2C19*17. In conclusion, in our study population of Asian patients, the CYP2C19*17 polymorphism was not associated with adverse clinical outcomes after PCI because of its low prevalence, the rarity of homozygotes, and the relatively low rate of adverse clinical events.