Abstract Background and Objective: Alzheimer’s disease (AD) is a weakening neurodegenerative disorder typified by increased b-amyloid (Ab) deposition and neuronal dysfunction causing to impaired learning and memory. Among proposed risk factors, induced oxidative stress is a main cause for incidence of the disease. The aim of this study was to determine the effects of the rosmarinic acid on learning and memory impairments with emphasis on its antioxidant properties. Materials and Methods: In the present study, the effect of the intraperitoneally administration of rosmarinic acid (10 and 20 mg/kg) on learning and memory impairments was assessed in intrahippocampal Ab(25–35)-injected rats. Results: The results showed that the intrahippocampal Ab(25–35)-injected rats exhibit lower spontaneous alternation score inY-maze tasks (pConclusion: This study indicates that rosmarinic acid pretreatment ameliorates Ab-induced impairment of learning and memory in rats via attenuation of oxidative stress burden.