Background: Drug-eluting stent (DES) implantation was reported to be associated with paradoxical peristent vasoconstriction in response to exercise or acetylcholine suggesting endothelial dysfunction. Endothelial dysfunction can result in atherosclerosis progression. We investigated whether plaque progression is accelerated in the neighboring segments after DES implantation compared with bare metal stent (BMS). Methods: We retrospectively evaluated 133 patients with stable angina who underwent successful stenting and completed follow-up coronary angiography (CAG). Patients were grouped into BMS (n=45) and DES (n=88). Late loss of minimal luminal diameter (MLD) of in-stent, proximal and distal stent edges (5 mm from stent) and proximal and distal neighboring segments (10 mm from stent edges) were measured in post-procedural and follow-up CAG. Results: Baseline clinical and angiographic characteristics were similar between 2 groups. Mean follow-up duration was 263짹176 days. Late loss of MLD in neighboring segments was significant in DES group, whereas not significant in BMS group. In-segment late losses were significant in both groups. But target vessel revascularization in neighboring segments was similar between 2 groups (4.4% vs 3.4%, p=NS). Conclusions: In contrast to BMS, DES implantation seems to be associated with plaque progression in the proximal and distal neighboring segment. But the clinical implication may be minimal.