Background and purpose <p>With the increasing global burden of dementia, it is crucial to address modifiable factors that contribute to the development and progression of dementia. In this article, we provide evidence from various types of research that delirium is an independent modifiable risk factor for dementia.</p> Methods <p>We synthesized recent literature concerning epidemiological, neuropsychological, and neurobiological research on the association between delirium and dementia.</p> Results <p>The body of literature provides evidence for an increased risk of cognitive impairment and dementia after delirium, even when no pre-existing cognitive impairment is objectified. Delirium and dementia share neurobiological pathways, involving, e.g., neuroinflammation, neuronal injury, dysregulated cerebral metabolism, and disintegration of brain networks. Multicomponent non-pharmacological interventions that reduce the risk of subsequent cognitive decline are feasible.</p> Conclusions <p>As of yet, ample evidence exists that delirium is an independent modifiable risk factor for dementia. More research is needed to further elucidate neurobiological and protective mechanisms underlying this association.</p>