Vascular dementia (VaD) refers to the loss of reasoning, planning, judgment, and memory as a result of reduced blood flow, inflammation, activation of immune cells, and neurodegenerative processes. Here, we tested the preventive effects of alpha-naphthoflavone (ANF) on a model of vascular dementia induced by four-vessel occlusion (4VO) in rats. Animals were treated orally for 5 consecutive days with 10 mg/kg of donepezil (a traditional therapeutic drug) and 40 and 80 mg/kg ANF. The treatment with ANF exerted effects that were similar to those induced by donepezil. This included prevention of cognitive impairment, alterations in the plasma levels of homocysteine and nitrate and the activity of acetylcholinesterase and myeloperoxidase and the tissue level of glutathione, and thiobarbituric acid reactive substances in the brain tissues. These findings suggest that herbal-derived ANF is as effective as traditional drugs in vascular dementia.