Background: Intimal hyperplasia contributes to late restenosis after coronary stenting. Vascular endothelial dysfunction may potentiate intimal hyperplasia after vascular injury. This study was designed to evaluate whether vascular endothelial function is associated with late restenosis after coronary stenting.Methods: In total 40 male patients, mean age of 70 years, angiographic restenosis (>50% of coronary luminal diameter stenosis) was determined quantitatively by angiography 6 months after coronary stenting. Forearm blood flow was measured by plethysmography at baseline (B), during reactive hyperemia (H), after sublingual NTG (N) and during reactive hyperemia after NTG (NH) in sequence. Another 10 age- and sex-matched subjects with normal coronary angiograms were studied as control (C).Results: There were 19 patients with (R) and 21 without late restenosis (NR). Basic data was similar between the 2 groups.Conclusion: Endothelial-dependent vasodilatation was selectively impaired in patients with late restenosis after coronary stenting, suggesting vascular endothelial dysfunction may play a role in restenotic process.