Objectives The aim of this study was to compare the efficacy and safety of balloon angioplasty and drug eluting stents for the treatment of in-stent restenosis (ISR). Methods From January 2006 to December 2009, PCI were performed in 91 patients (68 male, 76.4%, mean age 64.2짹11.3 years) with ISR lesion. Fifty seven patients (62.6%) were allocated in group I (balloon angioplasty) and 34 patients (37.4%) were allocated in group II (drug-eluting stent). We compared procedural and clinical follow-up outcomes between 2 groups. Results Baseline characteristics and lesion distribution were not different between both groups. Although ISR pattern was not different between both groups, reference vessel diameter was larger in group II than I (3.31짹0.58 mm vs. 2.76짹0.56 mm, P<0.05). And previous stent diameter was also larger in group II than I (3.14짹0.42 vs. 2.92짹0.35 mm, P<0.05). The overall success rate in group I and group II was 98.2% and 100%, respectively. The mean follow-up duration was 17.7 짹 13.1 months. The overall rate of major adverse cardiac event (MACE) was 12.1% (cardiac death : 1 patient, MI : 4 patients, TVR : 7 patients)., The rate of MACE, however, was not different between both groups (group I : 7 patients, group II : 4 patients, P=NS). The MACE free survival rate was also not different between both groups (figure). Conclusion Our data suggested balloon angioplasty showed compatible clinical outcomes compared to DES for treatment of ISR lesion.