With the increase of age in the world population, there has been an increase of neurodegenerative diseases and of cognitive impairment in the elderly, as well as of painful conditions, such as arthritis and pathological fractures. Therefore, the understanding of pain processing in dementia is an important issue which needs to be addressed in order to improve the quality of life of people who can not communicate. Recent works suggest that pain in dementia can not be considered as a single entity, since different types of dementia produce different changes of pain perception. For example, the most common types of dementia, Alzheimer's disease (AD) and vascular dementia (VD), are characterized by different pathophysiological substrates that have differential effects on pain. In fact, the main characteristic of AD is a dissociation between the sensory-discriminative and the affective-emotional components of pain. In other words, whereas AD patients show a normal sensory detection and pain threshold, they show an increase of pain tolerance along with reduced emotional responses. This sensory-emotional dissociation is well correlated to the neuropathological pattern of AD, in which neuronal degeneration is large in the limbic system and small in the primary somatosensory cortex. By contrast, VD patients do not show a constant pattern of pain perception. For example, whereas some VD patients are hyperalgesic to many procedures, some others show either sensory deficits or pain tolerance increase. This is due to the fact that VD is caused by multi-infarcts localized in cortical and/or subcortical regions with different and random patterns of spatial distribution. Consequently, the changes of pain perception depend on the localization of the vascular lesions. These findings have important clinical implications. In fact, different types of dementia require different therapeutic strategies in order to improve the quality of life of demented patients.