Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by memory impairment. Codonopsis lanceolata (C. lanceolata) has been employed clinically for lung inflammatory diseases such as asthma, tonsillitis, and pharyngitis. The present study was undertaken to evaluate the effect of fermented C. lanceolata (300, 500, and 800 mg/kg) on learning and memory impairment induced by scopolamine by using the Morris water maze and passive avoidance tests. To elucidate possible mechanism of cognitive-enhancing activity, we measured acetylcholinesterase (AchE) activity, brain-derived neurotrophic factor (BDNF), and cyclic AMP response element-binding protein (CREB) expression in the brain of mice. Administration of fermented C. lanceolata (800 mg/kg) led to reduced scopolamine-induced memory impairment in the Morris water maze and passive avoidance tests. Accordingly, the administration of fermented C. lanceolata inhibited AchE activity. Interestingly, the level of CREB phosphorylation and BDNF expression in hippocampal tissue of scopolamine-treated mice was significantly increased by the administration of fermented C. lanceolata. These results indicate that fermented C. lanceolata can ameliorate scopolamine-induced memory deficits in mouse and may be an alternative agent for the treatment of AD.