ObjectiveWe evaluated the efficacy of endovascular thrombectomy (EVT) on the functional outcome of patients with acute basilar artery occlusion and low posterior circulation acute stroke prognosis early computed tomography score (PC‐ASPECTS).MethodsWe identified patients with acute ischemic stroke due to basilar artery occlusion and PC‐ASPECTS of 6 or less, presenting within 24 h between August 2008 and April 2022. The primary outcome was a favorable functional outcome, defined as a modified Rankin Scale (mRS) score of 0–3 at 90 days. The secondary outcomes included an mRS score of 0–2, a favorable shift in the ordinal mRS scale, the occurrence of symptomatic intracranial hemorrhage (sICH), and mortality at 90 days. We compared the outcome of patients treated with EVT and those without EVT, using the inverse probability of treatment weighting methods.ResultsOut of 566 patients, 55.5% received EVT. In the EVT group, 106 (33.8%) achieved favorable outcomes, compared to 56 patients (22.2%) in the conservative group. EVT significantly increased the likelihood of achieving a favorable outcome compared to conservative treatment (relative risk [RR] 1.39, 95% confidence interval [CI], 1.11–1.74, p = 0.004). EVT was associated with a favorable shift in the mRS (RR 1.85, 95% CI, 1.49–2.29, p < 0.001) and reduced mortality without an increase in the risk of sICH. It did not have an impact on achieving an mRS score of 0–2.InterpretationPatients with acute basilar artery occlusion and a PC‐ASPECTS of 6 or less might benefit from EVT without an increasing sICH. ANN NEUROL 2024