This study aimed to evaluate the efficacy of endovascular treatment (EVT) in patients with secondary coma following acute basilar artery occlusion (comatose patients) and to identify the impact of the Glasgow Coma Scale (GCS) score on medical decisions.Patients from the Endovascular Treatment for Acute Basilar Artery Occlusion study were divided into comatose and noncomatose cohorts. The primary outcome was favorable functional independence (modified Rankin Scale [mRS] scores 0-3). The safety outcome was 90-day mortality. Subgroup analysis was performed to identify populations best suited for EVT. Multivariate logistic regression was used to identify independent predictive factors of clinical outcomes.Comatose patients who underwent EVT had more favorable functional outcomes and lower mortality compared with those who underwent standard medical treatment (functional outcomes: 15.98% vs 4.17%; mortality: 62.72% vs 82.29%). Moreover, EVT was associated with better outcomes in the cohort with GCS scores of 6-8 (mRS scores 0-3, 25.33% and mortality, 41.33%) than in the cohort with GCS scores of 3-5. Multivariate analysis indicated that EVT was an independent factor for favorable functional outcomes (adjusted OR 8.921, 95% CI 2.330-34.158) and mortality (adjusted OR 0.189, 95% CI 0.092-0.411) in comatose patients. The initial GCS score was an independent factor for favorable functional outcomes (adjusted OR 1.402, 95% CI 1.115-1.763) and mortality (adjusted OR 0.613, 95% CI 0.499-0.752) in comatose patients with EVT.EVT significantly improved the prognosis of comatose patients, and patients with GCS scores of 6-8 were found to benefit more from EVT than those with GCS scores of 3-5. The initial GCS score was an independent predictive factor for prognosis in comatose patients.