Introduction : Previous intravascular ultrasound(IVUS) studies have suggested that arterial remodeling may affect subsequent clinical outcome following bare metal stent implantation with angina pectoris and acute coronary syndrome (ACS). Although positive remodeling(PR) has shown to be a predominant pattern of lesion remodeling in patient with ACS, its impact in late outcome is unknown after implantation of DES. So we investigated impact of arterial remodeling in target lesion revascularization(TLR) and non-TLR following DES implantation in patients with ACS. Method : The study population consisted of 75 patients with ACS and de novo lesion treated with DES and evaluated by IVUS pre-, post-procedure. Clinical follow-up was done for minimum 24 months after index procedure. Results : Pre-intervention positive remodeling (PR) and intermediate remodeling (IR)/ negative remodeling (NR) were present in 49(65.3%) and 24(34.7%) patients, respectively. The remodeling index (RI) was 1.27짹0.21 in PR group and 0.84짹0.15 in IR/NR group. The EEM CSA, plaque plus media CSA in the minimal lumen CSA at pre-intervention were significantly larger in the PR group. Post intervention minimal lumen CSA was similar between PR and IR/NR. Although TLR free survival was similar between both groups, non-TLR free survival were significantlty higher in patient with IR/NR than in patients with PR (p=0.45). Conclusions : Two thirds of the coulprit lesions for acute coronary syndrome showed PR prior to intervention. Although optimal IVUS-guided stenting showed similar target lesion revascularization in lesion with PR and IR/NR, non-target lesion revascularization rate still higher in lesion with PR during 2 years following DES implantation.