Objective ·To investigate the early efficiency and safety of endovascular therapy (EVT) for patients with acute mild ischemic stroke with large vessel occlusion (LVO-MIS). Methods ·A total of 31 patients with LVO-MIS who received emergency EVT-assisted standard medical treatment at the Green Channel of Stroke in Shanghai Sixth People's Hospital, Shanghai Jiao Tong University School of Medicine from June 2016 to October 2022 were retrospectively included as endovascular therapy group (EVT group), and 32 LVO-MIS patients who only received standard medical treatment in the same period were selected as the control group. General clinical data and parameters related to EVT of the two groups were collected. The primary outcome was early efficacy, that is, the NIHSS at seventh day after treatment (d7NIHSS) score decreased by ≥3 points or directly to 0 points from baseline NIHSS score. Secondary outcomes included successful revascularization of blood vessels and early neurological deterioration (END), and safety outcomes included symptomatic intracranial hemorrhage (sICH) and mortality. The primary and secondary outcomes of the two groups of patients were analyzed to evaluate the early efficiency of EVT, and the safety evaluation indicators of the two groups of patients were analyzed to evaluate the safety of EVT. Kruskal-Wallis H test was used to analyze the NIHSS scores of 24 patients in the EVT group who underwent EVT before and after treatment. Results ·There was no statistically significant difference in the general clinical data between the two groups, as well as parameters related to EVT such as occlusion site, and onset-to-admission time. The baseline NIHSS score of the EVT group [5.0 (3.0, 5.0) points] was higher than that of the control group [3.5 (2.0, 5.0) points] (P=0.001), and their d7NIHSS score [1.0 (0, 3.0) points] was lower than that of the control group [2.0 (1.0, 5.8) points] (P=0.040). A total of 24 patients (38.1%) in the two groups achieved early efficacy, including 16 cases in the EVT group and 8 cases in the control group; and the early efficacy rate of the EVT group was higher than that of the control group (χ²=4.729, P=0.030). The END rate in the EVT group was lower than that in the control group (χ² =6.097, P=0.014), and there were 29 cases (93.5%) in the EVT group of patients whose blood vessels were successfully reopened. There was no statistically significant difference in sICH rate and mortality rate between the two groups. In the EVT group, there was a statistically significant difference (H=16.997, P=0.000) among the baseline NIHSS scores [5.0 (3.0, 5.0) points] of 24 patients, postoperative 24hNIHSS score [2.0 (0.3, 3.8) points] and d7NIHSS scores [1.0 (0, 2.8) points]. Conclusion ·EVT is safe and effective in treating LVO-MIS, and the early efficacy rate of EVT is superior to standard medicine treatment, with a lower rate of END and no increased risk of sICH.