Background and purpose: The aim of the present study was to investigate whether administration of edaravone during t-PA infusion can enhance early recanalization in acute stroke patients. Methods: This trial was undertaken as a multicenter, single blind, randomized, open-labeled study. Acute stroke patients with M1 or M2 occlusion within 3 h of onset were studied prospectively. The subjects were randomly allocated to edaravone (Edaravone group: when t-PA was intravenously infused, intravenous edaravone (30 mg) was started at the same time) and no edaravone (Non-Edaravone group). Early recanalization within 1 h after t-PA infusion and neurological recovery 24 h after t-PA infusion were compared between the two groups. Results: 40 patients (23 men. 17 women; mean age, 76.4 +/- 8.2 years, median 79 years) were enrolled; 23 patients were assigned to the Edaravone group and 17 to the Non-Edaravone group. Early recanalization was more frequently observed in the Edaravone group than in the Non-Edaravone group (56.5% vs. 11.8%, P=0.0072). Eight patients who underwent endovascular therapy immediately after t-PA infusion were excluded, and neurological recovery was analyzed. Remarkable and good recoveries were more frequently observed in the Edaravone group than in the Non-Edaravone group (80.1% vs. 45.5%, P=0.0396). Conclusion: Early recanalization and good neurological recovery were more frequently observed in the Edaravone group than in the Non-Edaravone group. These results demonstrate that administration of edaravone during t-PA infusion should enhance early recanalization in acute stroke patients. (C) 2011 Elsevier B.V. All rights reserved.