Delirium is a common, disabling medical condition that is associated with numerous adverse outcomes. A number of inter-related factors, including pre-existing cognitive impairment, usually contribute to the development of delirium in a particular susceptible individual. Non-pharmacological approaches to prevention typically target multiple risk factors in a systematic manner (multicomponent interventions). There is generally good evidence that multicomponent interventions reduce the incidence of delirium in hospital populations but there are limited data in people with dementia and those living in the community. It is likely that there is a differential effect of specific interventions in those with cognitive impairment (e.g. people with dementia may respond better to simpler, more pragmatic interventions rather than complex procedures) but this cannot be determined from the existing data. Targeted interventions focussed on hydration, medication rationalization and sleep promotion may also be effective in reducing the incidence of delirium, as well as the active involvement of family members in the care of the elderly hospitalized patient. Hospitalization itself is a potential risk factor for delirium and promising data are emerging of the benefits of home-based care as an alternative to hospitalization but this is restricted to specific sub-populations of patients and is reliant on these services being available.