BACKGROUND In recent years there has been a debate about the functional severity of restenosis of drug-eluting stents. The aim of the present study was to assess the functional severity of stenosis in patients with moderate angiographic restenosis after paclitaxel-eluting stents (PES) deployment. METHODS AND RESULTS Forty-two patients with moderate angiographic restenosis at the in-stent segment and/or approximately 5mm from the stent edge were enrolled. For comparison, furthermore, 42 patients with de novo stenosis lesions matched for angiographic severity were assigned to the control group. Quantitative coronary angiography and functional assessment using fractional flow reserve (FFR) were performed. Although percent diameter stenosis was not significantly different between the 2 groups (PES group, 40.6±11.2%; de novo group, 40.6±9.0%, P=0.981), the functional severity of stenosis was significantly less in the PES group than in the de novo group (FFR: PES group, 0.86±0.07; de novo group, 0.79±0.10, P=0.002). CONCLUSIONS FFR was preserved in patients with moderate angiographic restenosis after PES deployment, and the functional severity of restenosis is often limited. Therefore, revascularization should be performed with caution for patients with moderate angiographic restenosis after PES deployment.