Abstract: AIM To perform a retrospective analysis of the efficacy and safety of percutaneous coronary intervention(PCI) treatment in long duration occlusions patients with chronic total occlusions(CTO). METHODS Patients with CTO confirmed by coronary angiography and treated by PCI between January 2006 and June 2007 were enrolled in our study. The clinical data, outcomes of PCI, perioperative complications and the incidence of major adverse cardiac events(MACE) during follow-up were retrospectively analyzed between Group One (the occlusion time was equal to or less than 12 months, n=135) and Group Two(the occlusion time was longer than 12 months, n=223). RESULTS The proportions of senile patients and female patients and the proportions of patients with hypertension and diabetes mellitus in Group Two were higher than those in Group One. The ratios of CTO characterized with absolute occlusion, stump missing, ≥15 mm in length and bridging collaterals in Group Two were higher than those in group One. No statistical difference was found in the success rate of lesions and patients between the two groups(91% vs 95%, 93% vs 97%). No death occurred during operation, no major adverse cardiac events(MACE) occurred after operation in hospital and no patients undertook emergency coronary artery bypass graft(CABG) in the two groups. No statistical difference was found in the MACE occurrence of one year follow up. CONCLUSION A relatively high success rate of PCI and good short-term clinical outcomes can be achieved in patients with long duration of occlusion.