Forsythiaside is a polyphenolic constituent of the fruits of Forsythia suspense Vahl which are widely used as anti-inflammatory herbal raw materials in traditional Chinese medicine. In the present study, the authors assessed the effects of forsythiaside on learning and memory impairments induced by scopolamine using a passive avoidance and the Morris water maze tests in mice. Drug-induced amnesia was induced by scopolamine treatment (1 mg/kg, i.p.). Forsythiaside (10 mg/kg, p.o) administration significantly prevented scopolamine-induced step-through latency reduction in the passive avoidance test and scopolamine-induced increased escape latency in the Morris water maze test (p<0.05). Moreover, in an ex-vivo study, forsythiaside treatment (10 mg/kg, p.o) significantly reduced the increase of thiobarbituric acid reactive substance levels induced by scopolamine (p<0.05). Taken together, the present study suggests that forsythiaside could be useful for the treatment of cognitive impairment, and that its beneficial effects are mediated, in part, by its antioxidative properties.