Authors of this study aimed to investigate the efficacy and safety of endovascular treatment (EVT) versus standard medical treatment (SMT) alone in patients with acute basilar artery occlusion (BAO) and moderate deficit (National Institutes of Health Stroke Scale [NIHSS] score 10-19).Patients with moderate deficit caused by acute BAO in the period from January 2014 to May 2019 were included in the study. The patients were divided into groups based on treatment: EVT plus SMT group or SMT-alone group. The primary outcome was favorable functional outcome (modified Rankin Scale score 0-3) at 90 days, and safety outcomes were symptomatic intracerebral hemorrhage (sICH) and mortality at 90 days.A total of 173 patients had moderate deficits, 128 of whom had been treated with EVT and 45 with SMT alone. EVT was associated with a significant higher proportion of 90-day favorable outcomes compared with SMT (adjusted odds ratio [aOR] 4.09, 95% CI 1.39-12.04, p = 0.011). Younger age (aOR 0.96, 95% CI 0.92-0.99, p = 0.017), absence of diabetes mellitus (aOR 0.35, 95% CI 0.12-0.99, p = 0.048), higher baseline posterior circulation Acute Stroke Prognosis Early Computed Tomography Score (pc-ASPECTS; aOR 1.48, 95% CI 1.07-2.05, p = 0.018), and modified Thrombolysis in Cerebral Infarction (mTICI) score of 2b-3 (aOR 15.15, 95% CI 3.07-74.72, p = 0.001) were independent factors for a favorable outcome in the EVT group. Rates of mortality and sICH were comparable in the EVT and SMT groups.EVT leads to improved outcomes compared to those with SMT alone. Younger age, absence of diabetes mellitus, higher baseline pc-ASPECTSs, and mTICI score of 2b-3 were associated with better functional outcome in the EVT group.