This article, the fifth in a series on dementia, discusses the principles of management and treatment of people with dementia. It describes how to proceed after a diagnosis of dementia has been made in the early stages of the condition, and general measures to maintain physical and mental health. Drug therapy for cognitive dysfunction is explained in the context of the National Institute for Health and Care Excellence guidance, and strategies for managing depression and psychotic symptoms are outlined. Non-pharmacological approaches are often effective. For behavioural problems such as agitation and aggression, it is important to try to understand any underlying factors. In general, the most important strategy is to avoid excessive prescribing.