Background Chronic total occlusion (CTO) intervention is still challenging because of the limited procedural success rate and higher target failure. It is not clear whether single or multi-vessels will have impact on the angiographic and clinical outcomes of CTO intervention in drug eluting stent (DES) era.Methods A total of 180 patients (pts) underwent CTO intervention were divided into the two groups according to number of target vessels (Multi-vessels: n=105 pts, Single vessel: n=75 pts). Multi-vessel was defined as two or more target vessels. In-hospital and 6-month outcomes were compared between the two groups.Results The baseline clinical characteristics were similar between the two groups except hyperlipidemia was more common in multi-vessels group (19.4% vs 8.0%, p=0.03). The overall procedural success rate was similar between the two groups. Procedural characteristics and procedure related complications were not different between the two groups. At 6 months, these two groups showed similar angiographic and clinical outcomes including the rate of binary restenosis, late loss, death, Q-myocardial infarction (Q-MI), target lesion and vessel revascularization (TLR & TVR) and major adverse cardiac events (MACE, Table).Conclusions The safety profile and mid-term outcomes of CTO pts with multi target vessels were with those of CTO pts with single target vessel. The number of target vessels may have very limited impact on the mid-term outcomes possibly due to high procedural success rate at index procedure and the use of DESs. Long-term follow up with larger population will be necessary to get the clear conclusion.