Chronic total occlusions (CTO) are common and found in approximately one-third of patients with significant coronary disease who undergo angiography [1]. Previous studies have demonstrated the importance of revascularization of CTOs, with improvement in anginal symptoms, exercise capacity, left ventricular function, and long-term survival [2–5]. Despite the marked reduction in restenosis realized with drug-eluting stents [6,7], the clinical efficacy is hampered by procedural failure mainly due to inability to cross the occlusion with a guide wire. Reasons for difficulties to cross the occlusion include the inability to detect the true intraluminal passage, which may not be well visualized using conventional coronary angiography. Recently, several studies indicate high quantitative and qualitative diagnostic accuracy of multislice computed tomography (MSCT) in comparison to quantitative coronary angiography in a broad spectrum of patients [8–10]. Moreover, with increasing accuracy, MSCT offers a threedimensional anatomical course of the coronary arteries as well as plaque morphology (calcification), which may improve the clinical success rate of percutaneous coronary intervention (PCI) for CTO. Between July 2004 and June 2005, 107 consecutive patients with CTO were treated by a single operator in our institute. CTO was defined as complete interruption of the