Background: A multicenter, double-blind, placebo-controlled study was conducted to assess the efficacy and safety of fasudil, a Rhokinase inhibitor (RKI), in the treatment of acute ischemic stroke. Methods: A total of 160 patients, who were able to receive drug treatment within 48 h of acute ischemic stroke onset were enrolled. Patients received either 60 mg fasudil or a placebo (saline) by intravenous injection over 60 min, twice daily for 14 days. The primary end points were neurological status at 2 weeks after the start of treatment, and clinical outcome at 1 month after the onset of symptoms. Results: Fasudil treatment resulted in significantly greater improvements in both neurological functions (p = 0.0013), and clinical outcome (p = 0.0015). There were no serious adverse events reported in the fasudil group. The average trough value (12 h values)of active metabolite hydroxyfasudil, another RKI, in healthy elderl y volunteers receiving 60 mg of fasudil was 0.077 μM a concentration well above that needed to inhibit Rho-kinase (0.025-0.05 μM). Conclusion: Treatment wit h fasudil within 48 h of acute ischemic stroke onset significantly improved the patient’s clinical outcome. This study found fasudil to be a useful and safe dr ug for patients with acute ischemic stroke. Further evaluations, for example, 3 -month functional outcomes in a larger clinical trial, may help to define the e fficacy of fasudil in acute ischemic stroke. Background: A multicenter, double-blind, placebo-controlled study was conducted to assess the efficacy and safety of fasudil, a Rhokinase inhibitor (RKI), in the treatment of acute ischemic stroke. Methods: A total of 160 patients, who were able to receive drug treatment within 48 h of acute ischemic stroke onset were enrolled. Patients received either 60 mg fasudil or a placebo (saline) intravenous injection over 60 min, twice daily for 14 days. The primary end points were neurological status at 2 weeks after the start of treatment, and clinical outcome at 1 month after the onset of symptoms. Results: Fasudil treatment resulted in significantly greater improvements in both neurological functions (p = 0.0013), and clinical outcome (p = 0.0015). adverse events reported in the fasudil group. The average trough value (12 h values) of active metabolite hydroxyfasudil, another RKI, in healthy elder volunteers receiving 60 mg of fasudil was 0.077 μM a concentratio Conclusion: Treatment wit h fasudil within 48 h of acute ischemic stroke onset significantly improved the patient’s clinical outcome. This study found fasudil to be a useful and safe dr ug for patients with acute ischemic stroke. Further evaluations, for example, 3-month functional outcomes in a larger clinical trial, may help to define the e fficacy of fasudil in acute ischemic stroke.