This chapter reviews available evidence for a cognitive improvement associated with cholinesterase inhibitors (ChEI) and memantine in vascular dementia (VaD) and Alzheimer's disease (AD) with cerebrovascular disease (CVD). It discusses cognitive changes associated with the dementia stage of VaD. A cholinergic deficit has been demonstrated in VaD, independently of any concomitant AD pathology. Cholinergic structures are vulnerable to ischemic damage. Donepezil and rivastigmine have been studied using randomized clinical trials in VaD and galantamine in a mixed population of VaD and AD with CVD. Sub-group analyses by radiological findings at baseline showed that the cognitive treatment effect for memantine was more pronounced in the small-vessel type group without cortical infarctions by computed tomography (CT) or magnetic resonance imaging (MRI). Cognitive tests should be performed before treatment, preferable using those with an executive component, to be repeated at set intervals in the order of six months.