The post-endovascular treatment outcomes of thrombotic lesions remain unclear. This study aimed to investigate the effects of thrombotic lesions on post-endovascular treatment outcomes in patients with non-acute aortoiliac total occlusions. Methods: This subanalysis of a multicenter prospective observational registry study included patients from 64 institutions in Japan between April 2014 and April 2016. A total of 346 patients (394 limbs; median age, 72 years), including 186 men, underwent endovascular treatment for non-acute aortoiliac total occlusions and were included. The patients were classified as having thrombotic or non-thrombotic lesions. The primary (1-year primary patency rate) and secondary (1-year overall survival rate) endpoints were evaluated. Results: Thrombotic lesions were identified in 18.5% (64/346) of the patients. The 1-year primary patency (85.9% versus 95.4%, log-rank p .001) and overall survival (90.6% versus 97.9%, log-rank p .003) rates were significantly lower in the thrombotic group than in the non-thrombotic group. Thrombotic lesions had significant effects on the post-endovascular treatment outcomes, with adjusted hazard ratios of 3.91 (95% confidence interval, 1.64-9.34, p .002) for primary patency and 4.93 (95% confidence interval, 1.59-15.3, p .006) for all-cause mortality. Conclusions: Thrombotic lesions were associated with 1-year restenosis and all-cause mortality after endovascular treatment for non-acute aortoiliac total occlusions. Endovascular treatment strategies should be carefully planned for patients with thrombotic lesions. disease, and favorable post-EVT outcomes were reported 1-2). Among patients undergoing EVT for AI lesions, 24% have chronic total occlusions (CTOs) 1). Generally, CTOs are hard lesions containing rigid