Ginsenoside Rb₁ (GRb₁), a major component of the traditional herb ginseng, has been reported to show a neuroprotective effect in a rodent ischemic model. The purpose of this study was to investigate effects of GRb₁ on early and delayed brain injuries in a non-human primate thromboembolic stroke model. Thromboembolic stroke was induced by occlusion of the middle cerebral artery by injection of an autologous blood clot into the left internal carotid artery. GRb₁ (300 μg/kg per day, i.v.) and vehicle were administered from 7 days before embolization to the day following embolization (total: 8 times). Neurological deficits were observed at 1, 6, and 24 h and at 2, 4, and 7 days after embolization. At 7 days after embolization, neuron damage in the peri-infarct area and core region were assessed by NeuN, TUNEL, and GFAP staining. GRb₁ improved the skeletal muscle coordination score of the neurologic deficits (median: GRb₁ vs vehicle = 10 vs 12, P<0.05). In the GRb₁ group, positive neurons expressed by NeuN staining were noted in the ischemic peri-infarct area, and TUNEL- and GFAP-positive cells significantly decreased, when compared with vehicle. These results demonstrated that GRb₁ ameliorated both early and delayed injuries in the thromboembolic stroke model in non-human primates.