Objectives: The purpose of this study was to evaluate endothelial function after post-dilation of bare-metal stents with paclitaxel-coated balloons (PCB) or nondrug-coated balloons (non-DCB) in a porcine model. Background: DCB are an attractive alternative to drug-eluting stents because they provide short duration of drug exposure, while potentially inhibiting in-stent restenosis. Drug-eluting stents are associated with impaired endothelial function. It is unknown whether this abnormal vasomotor function is mitigated by reduced duration of drug exposure. Methods: Thirteen pigs underwent bare-metal stent implantation (arteries, n = 30), followed by post-dilation with either PCB (SeQuent Please, B. Braun Melsungen AG, Berlin, Germany) (n = 17) or non-DCB (n = 13). Five pigs with unstented arteries (n = 14) were controls. Coronary vasomotion was assessed 1 month after stent implantation, using acetylcholine (Ach) and nitroglycerin. Measurements were obtained for distal segments. Results: Angiographic late loss and histological area stenosis were similar between PCB and non-DCB. However, the percentage of diameter change in response to Ach was diminished with PCB (p < 0.05), when compared with either non-DCB or naive arteries. There was no difference between non-DCB and naive arteries. Inflammatory score and intramural fibrin grading were significantly greater in PCB than non-DCB (p < 0.05). Additionally, inflammatory cell infiltration in the stented segments correlated with the degree of percentage of diameter change in response to Ach, at distal regions. Conclusions: Post-dilation of bare-metal stents with PCB was associated with impaired vasodilatory response to Ach distal to the treated segments. Vasodilatory response after post-dilation with non-DCB was similar to control arteries. © 2011 American College of Cardiology Foundation.