Backgrouds: Optical coherence tomography (OCT) outperforms intravascular ultrasonography (IVUS) in the identification of stent malapposition, which was not undetected by IVUS due to limited resolution. The objective of the present study is to evaluate the clinical outcomes of poststent malappositon detected by OCT, but undetected by IVUS, in patients underwent drug eluting stent (DES) implantation. Methods: 42 patients treated with zotarolimus eluting stent (ZES) or non-ZES [sirolimus eluting stent (SES) or paclitaxel eluting stent(PES)] were consecutively enrolled in this study between August 2007 and August 2008. Immediate postprocedural OCT images were obtained in 11 patients in the non-ZES group and 31 patients in the ZES group. Follow-up OCT images were obtained at 6-9 months after non-ZES deployment and at 3 months after ZES deployment. As a composite of metal strut and polymer, the thickness of each type of DES differ, malapposed stent struts as struts with detachment from the vessel wall ���160 關m for SES, ���130 關m for PES, ���90關m for ZES. The number and percent of malapposition strut, mean stent area, mean extra-stent malapposition area for both non-ZES groups and ZES groups were compared. Also, we assessed major adverse cardiac events (MACE)[all-cause death, non-fatal myocardial infarction(MI), and target vessel revascularization (TVR)] and stent thrombosis in the two groups. Results: The baseline characteristics of the patients included in the analysis were comparable. But, Patients were predominantly male in the non-ZES group. Also, the incidence of ACS was 100% in the non-ZES group compared with 3.2% and 66.7% in the ZES group, respectively (p = 0.021). All imaging procedures were performed without complication or adverse events. Total measured stent length was 1512 mm including 13804 struts (2711 in non-ZES group and 11093 in ZES group). Significant differences in the percent of malapposed and mean extra-stent malapposition area at immediate postprocedure and follow-up OCT were found between the two groups. Change in mean extra-stent malapposition area (mm2) were -0.093 짹 0.093 in the non-ZES groups and -0.012 짹 0.027 in the ZES groups (p=0.004). But, the incidence of major adverse cardiac events at one year was comparable in the two groups. There was no stent thrombosis in this analysis. Conclusion: The mean extra-stent malapposition area was decreased at follow-up OCT in the two groups, without stent thrombosis. Stent malapposition immediately following DES implantation was not associated increased adverse clinical events in this study.