Abstract： Background Coronary chronic total occlusion (CTO) remains one of the most challenging lesion subsets in interventional cardiology, even with the development of medical device and operator expertise. This study was conducted to examine the relationship between lesion characteristics and procedural success and the incidence of in-hospital major adverse cardiac events (MACE) after percutaneous coronary intervention (PCI) for CTO.Methods Clinical and coronary angiographic data of 1263 patients with CTO who underwent PCI between June 1995 and December 2005 in Shenyang General Hospital of PLA were retrospectively analyzed.Results There were 1625 CTO lesions located in 1596 vessels with a mean occlusion time of 48.9 months. A total of 1647 coronary stents were implanted to the target lesions. The overall patient and lesion success rates were 90.8 % (1147/1263) and 88.9 % (1445/1625), respectively. The success rate of PCI was declined with long duration of occlusion, abrupt missing stump, bridging collaterals ≥15 mm in occluded length, moderate to severe calcification or tortuosity and ostial or distal location of CTO lesions (P＜ 0.05). Procedural failure occurred in 116 patients, caused by impossibility of guide-wire (81.0%) or balloon (19.0%) to pass through the occlusion.There was no death during procedure, but 2 patients suffered from acute stent thrombosis and other 9 patients had acute or late pericardial perforation. Those complications were all successfully treated. After procedure, 3patients died, 4 experienced urgent target vessel revascularization because of subacute stent thrombosis and 1underwent coronary bypass graft surgery due to coronary fistula during in-hospital period. The overall in-hospital MACE rate was 0.6% (8/1263). Drug-eluting stents were used in 198 patients without in-hospital MACE.Conclusions In an experienced heart center, it is possible to obtain a relatively high success rate of PCI and favorable clinical outcomes for patients with coronary CTO lesions.