BACKGROUND AND OBJECTIVE: Percutaneous transluminal coronary angioplasty of chronic total occlusion has been limited by a relatively low success rate and a high restenosis rate. This study investigated procedural outcome, factors predictive of procedural success and safety of coronary angioplasty for chronic total coronary occlusion. MATERIALS AND METHODS: The study population was composed of 45 lesions attempting PTCA with or without stent implantation for recanalization of chronic total coronary occlusion between January 1997 and July 1999. The clinical and angiographic data of the 45 lesions were reviewed. The results of successful PTCA in 28 lesions were compared with those in 17 lesions whose PTCA was failed. RESULTS: The overall success of balloon angioplasty and stenting was achieved in 28 lesions (62.2%) and did not differ significantly by clinical variables. The most common cause of failure of balloon angioplasty was inability to pass the guide wire across the occlusion( 14 of 23 lesions, 61%). Procedural success was more common in patients with occlusions with a tapered entry configuration(77.2% vs. 47.8%, p=.042), with lesions without side branches(82.3% vs. 50%, p=.03). Multiple logistic regression analysis identified the absence of side branch(p<0.01) and the presence of a tapered entry configuration(p<0.05) as independent predictors of procedural success. One case(2.2%) needed emergency coronary bypass surgery after failure to recanalize the occluded vessel. There was no Q wave acute myocardial infarction, death. CONCLUSIONS: The favorable cases(>60%) of chronic total coronary occlusions can be successfully dilated by balloon angioplasty with or without stent implantation, with a major complication rate of 2.2%. Therefore, with careful patient selection, we need to try the aggressive recanalization for chronic total coronary occlusion.