In our daily practice, a stent overlap is encountered in approximately one-third of patients undergoing percutaneous coronary intervention (PCI) due to a long lesion, edge dissection, or incomplete stent coverage. In the bare-metal stent (BMS) era, the clinical outcomes of patients treated with overlapping stents were poorer than that of patients treated with a single BMS, mainly due to the increased risk of restenosis. Even though the restenosis rate has been dramatically reduced by introduction of the first-generation drug-eluting stent (DES), stent overlap is still a high-risk factor for long-term prognosis. Numerous reasons have been postulated, including localized peaks of drug/polymer, mal-mechanical reactions such as stent fracture, and thickening of stent metal, which can disturb flow dynamics. To overcome these issues, new stent technologies, including new antiproliferative drugs, thinner and flexible scaffolds, and better biocompatible polymers, have been developed, which can provide better clinical outcomes. However, data from a recent large registry indicated a significant increase in the major adverse cardiac event rate in multiple overlapping stenting than in single stenting treated with a second-generation DES (multiple stent overlapping 7.1% vs. single stent 1.5%, P < 0.001).