Endovascular thrombectomy has been effective in reducing stroke-related disability in high-income countries. This trial in the public health care system of Brazil, a developing country, showed similar effectiveness in patients treated within 8 hours after the onset of symptoms. Background Randomized trials involving patients with stroke have established that outcomes are improved with the use of thrombectomy for large-vessel occlusion. These trials were performed in high-resource countries and have had limited effects on medical practice in low- and middle-income countries. Methods We studied the safety and efficacy of thrombectomy in the public health system of Brazil. In 12 public hospitals, patients with a proximal intracranial occlusion in the anterior circulation that could be treated within 8 hours after the onset of stroke symptoms were randomly assigned in a 1:1 ratio to receive standard care plus mechanical thrombectomy (thrombectomy group) or standard care alone (control group). The primary outcome was the score on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) at 90 days. Results A total of 300 patients were enrolled, including 79 who had undergone thrombectomy during an open-label roll-in period. Approximately 70% in the two groups received intravenous alteplase. The trial was stopped early because of efficacy when 221 of a planned 690 patients had undergone randomization (111 to the thrombectomy group and 110 to the control group). The common odds ratio for a better distribution of scores on the modified Rankin scale at 90 days was 2.28 (95% confidence interval [CI], 1.41 to 3.69; P=0.001), favoring thrombectomy. The percentage of patients with a score on the modified Rankin scale of 0 to 2, signifying an absence of or minor neurologic deficit, was 35.1% in the thrombectomy group and 20.0% in the control group (difference, 15.1 percentage points; 95% CI, 2.6 to 27.6). Asymptomatic intracranial hemorrhage occurred in 51.4% of the patients in the thrombectomy group and 24.5% of those in the control group; symptomatic intracranial hemorrhage occurred in 4.5% of the patients in each group. Conclusions In this randomized trial conducted in the public health care system of Brazil, endovascular treatment within 8 hours after the onset of stroke symptoms in conjunction with standard care resulted in better functional outcomes at 90 days than standard care alone. (Funded by the Brazilian Ministry of Health; RESILIENT ClinicalTrials.gov number, NCT02216643.)