Objective To investigate the safety and effectiveness of endovascular treatment in patients with acute ischemic stroke due to large vessel occlusion(AIS-LVO)over 24 h after onset.Methods The clinical data of AIS-LVO patients who received endovascular treatment in Neurovascular Center of The First Affiliated Hospital of Naval Medical University from Jan.2018 to Dec.2022 were retrospectively analyzed,including baseline characteristics,imaging findings,treatment,degree of vascular recanalization(modified thrombolysis in cerebral infarction grade 2b and 3 for successful recanalization)and prognosis.Results A total of 57 patients were included,including 42 males and 15 females,aged from 30 to 84 years old.The most common risk factors were hypertension(39 cases,68.4%),followed by smoking history(24 cases,42.1%),diabetes mellitus(17 cases,29.8%),previous stroke history(16 cases,28.1%),and atrial fibrillation(9 cases,15.8%).Before treatment,the National Institutes of Health stroke scale score was 12.84±7.04,and the Alberta Stroke Program early computed tomography score was 9.00(7.00,10.00).Vascular occlusion sites included middle cerebral artery occlusion in 27(47.4%)cases,internal carotid artery occlusion in 24(42.1%)cases,and tandem lesions in 6(10.5%)cases.The time from onset to femoral artery puncture was 38.30(28.17,53.71)h,and the time from femoral artery puncture to vascular recanalization was 52.00(38.50,92.50)min.General anesthesia was the main anesthesia method,accounting for 64.9%(37/57).The etiological types of stroke were mainly large artery atherosclerosis(38 cases,66.7%),cardiogenic embolism(9 cases,15.8%),unknown causes(6 cases,10.5%),and other clear causes(4 cases,7.0%).Mechanical thrombectomy was the first choice in 41(71.9%)cases,balloon dilatation/stenting was used in 35(61.4%)cases,of which 15(26.3%)cases were the first choice.Finally,53(93.0%)cases were recanalized successfully.In terms of complications,1(1.8%)case had symptomatic intracranial hemorrhage.The 90-d prognosis rate was 59.6%(34/57),and 3(5.3%)cases died.Conclusion Endovascular treatment for AIS-LVO patients over 24 h after onset has high recanalization rate and good safety,but it still needs to be further verified by randomized controlled trials.