IVUS is one of the widely used intracoronary imaging devices to provide more reproducible and accurate information about coronary anatomy than angiography in current practice.8 Optimal stent expansion assessed by intravascular ultrasound (IVUS) has been reported as an important factor to prevent stent thrombosis or restenosis.9 Accordingly, there have been many studies to evaluate the procedural or clinical benefit of IVUS guided angioplasty. However, The clinical benefit of IVUS-guided angioplasty with stent implantation is still in a controversy. In the previous studies, IVUS-guided stent implantation showed positive or negative beneficial effect on clinical outcomes according to their study subjects. However, the stents used in the previous studies are less useful in current practice of cardiology and there is lack of data of 3rd generation DES, which have different stent profiles and outcomes with their predecessors.