This study investigated the effect of aged garlic extract (AGE) on spatial learning and memory ability using Morris water maze (MWM) test in amyloid-ß(Aß) induced-neurotoxicity rats. Pretreatment of AGE at oral doses of 125, 250 and 500 mg/kg for 8 weeks significantly prevented the learning and short-term memory impairment in Aß-induced neurotoxicity rats. Histological analysis has shown that pretreatment of AGE reversed the neuron loss in the CA1 and CA2 regions of hippocampus of Aß-induced neurotoxicity in a comparable effect of ascorbic acid. By DPPH and FRAP determination, AGE had high antioxidative activity. Pretreatment of AGE caused significant increases of superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, no significant change in catalase (CAT) activity, and a significant decrease of malondialdehyde (MDA) level of the Aß-induced rat brain homogenate. The results suggest that AGE ameliorates the cognitive dysfunction in Aß- induced neurotoxicity rats via its antioxidative effect.