BACKGROUND: The REVASCAT trial and other studies have shown that the neurovascular thrombectomy improves outcomes at 90 days post stroke. However, whether the observed benefit is sustained in the long term remains unknown. We report the results of the prespecified 12-month analysis of the REVASCAT trial. METHODS: Patients with acute ischaemic stroke who could be treated within 8 h of symptom onset were randomly assigned to medical therapy (including intravenous alteplase when eligible) and neurovascular thrombectomy with Solitaire FR or medical therapy alone. The main secondary outcome measure at 1 year follow-up was disability, measured using the modified Rankin Scale (mRS), ranging from 0 (no symptoms) to 6 (death) with categories 5 (severe disability) and 6 (death) collapsed into one category (severe disability or death), analysed as the distribution of the mRS. Additional prespecified secondary outcome measures included health-related quality of life measured with the EuroQol five dimensions questionnaire (EQ-5D) utility index (ranging from -0·3 to 1, higher values indicate better quality of life), the rate of functional independence (mRS 0-2), and cognitive function measured with the Trail Making Test (reported elsewhere). Treatment allocation was open label but endpoints at 12 months were assessed by masked investigators. The trial was registered at ClinicalTrials.gov, number NCT01692379. FINDINGS: From Nov 24, 2012, to Dec 12, 2014, 206 patients were randomly assigned to medical therapy plus endovascular treatment (n=103) or medical treatment alone (n=103), at four centres in Catalonia, Spain. At 12 months post randomisation, based on 205 of 206 outcomes available at 12 months, thrombectomy reduced disability over the range of the mRS (common adjusted odds ratio [aOR] 1·80, 95% CI 1·09-2·99), and improved functional independence (mRS=0-2; 45 [44%] of 103 patients vs 31 [30%] of 103 patients; aOR 1·86, 95% CI 1·01-3·44). Health-related quality of life was superior in the thrombectomy group (mean EQ-5D utility index score, 0·46 [SD 0·38] in the thrombectomy group vs 0·33 [0·33] in the control group, difference 0·12 [95% CI 0·03-0·22]; p=0·01). 1-year mortality was 23% (24 of 103 patients) in the thrombectomy group versus 24% (25 of 103 patients) in the control group. INTERPRETATION: At 12 months follow-up, neurovascular thrombectomy reduced post-stroke disability and improved health-related quality of life, indicating sustained benefit. These findings have important clinical and public health implications for evaluating the cost-effectiveness of the intervention in the long term. FUNDING: Fundació Ictus Malaltia Vascular through an unrestricted grant from Medtronic.