Neuroprotective effects of parthenocissin A (PA), a novel antioxidant and free radical scavenger, were studied in a transient middle cerebral artery (MCA) occlusion model in rats for the first time. The animals were treated intraperitoneally with PA at 2.5, 5 or 10 mg/kg, for both 30 min before MCA occlusion and 6 h after reperfusion. The MCA was occluded for 1 h in anesthetized Sprague-Dawley rats. Compared with vehicle-treated controls, MCA occluded animals treated with PA showed dose-dependent reductions in brain infarction size with improved neurological and motor outcome. Biomedical assay showed that the PA treatment suppressed lipid peroxidation and restored superoxide dismutase (SOD) activity in brain tissue. In addition, the ischemia/reperfusion (I/R) induced elevation of nitric oxide (NO) production and nitric oxide synthase (NOS) activity in brain tissue was also inhibited. Thus, PA demonstrated a neuroprotective effect in the I/R model and the beneficial effects of the compound may result from the reduction of oxidative stress and the inhibition of NO production induced by I/R. The neuroprotective effects of PA have highlighted the potential use of stilbene oligomers in stroke therapy.