BACKGROUND : Subintimal percutaneous transluminal angioplasty (SI-PTA) is one of the treatment options for long segment occluded lower limb artery. We sought to investigate factors influencing patency following subintimal angioplasty in patients with severe lower extremity occlusive vascular disease. METHODS : Between 2006 and 2008, 63 consecutive SI-PTA (53 patients) were done in patients with severe occlusive peripheral artery disease. Medical records, angiographic, and non-invasive studies were reviewed in detail up to 12months post-intervention. Atherosclerosis risk factors, the characteristics of peripheral artery lesions, length of occlusion, run-off and calcification of the artery were recorded. Lesions were classified according to TransAtlantic Inter-Society Consensus (TASC) Criteria (II-2007 versions). RESULTS : The morphology of occlusions in all patients were Type C (12 cases, 20%) or type D (48 cases, 80%). The incidence of infrainguinal lesion (45 cases, 71.4%) were higher than that of iliac artery occlusive lesion (18 cases, 28.6%). The procedural success rate was 93%. No major or minor vascular complication was observed. The primary patency rate at 12 months was 62%. TASC C/D, the lengths of occlusion, distal SFA involving lesions, post-procedural run-off vessels, calcified lesions were chosen as significant variables related to patency by univariate analysis (p=0.014, <0.001, <0.001, <0.001, 0.007, respectively). According to multivariate analysis, the factors that affect patency were the length of occlusion, distal SFA involving lesions, and post-procedural run-off vessels (p=0.022, 0.007, 0.011, respectively). The length of angioplasyy (p=0.781) was not related to 12-months patency. CONCLUSIONS : The lengths of occlusion, distal SFA involving lesion, and post-procedural run-off vessels were strong independent predictors for reocclusion in TASC C and D disease that underwent SI-PTA.