This study sought to evaluate the optimal treatment for in-stent restenosis (ISR) of drug-eluting stents (DESs). This is a prospective, multicenter, open-label, randomized study comparing the use of drug-eluting balloon (DEB) versus second-generation everolimus-eluting stent for the treatment of DES ISR. The primary end point was in-segment late loss at 9-month routine angiographic follow-up. A total of 172 patients were enrolled, and 74 (43.0%) patients underwent the angiographic follow-up. The primary end point was not different between the 2 treatment groups (DEB group 0.15±0.49 mm vs DES group 0.19±0.41 mm, P=.54). The secondary end points of in-segment minimal luminal diameter (MLD) (1.80±0.69 mm vs 2.09±0.46 mm, P=.03), in-stent MLD (1.90±0.71 mm vs 2.29±0.48 mm, P=.005), in-segment percent diameter stenosis (34%±21% vs 26%±15%, P=.05), and in-stent percent diameter stenosis (33%±21% vs 21%±15%, P=.002) were more favorable in the DES group. The composite of death, myocardial infarction, or target lesion revascularization at 1 year was comparable between the 2 groups (DEB group 7.0% vs DES group 4.7%, P=.51). Treatment of DES ISR using DEB or second-generation DES did not differ in terms of late loss at 9-month angiographic follow-up, whereas DES showed better angiographic results regarding minimal MLD and percent diameter stenosis. Both treatment strategies were safe and effective up to 1year after the procedure.