Objective: This article analyzes the natural history of wandering behavior throughout the course of dementia. Design: Prospective, 10-year, longitudinal study of wandering behavior in dementia, with autopsy follow-up. Setting: Participants with dementia, living at home with a carer. All lived in Oxfordshire, UK. Participants: Eighty-six people with dementia who were living at home with a carer and who were able to walk unaided at entry to study. Measures: At 4-monthly intervals, the carers were interviewed using the Present Behavioural Examination to assess wandering behavior were distinguished. Results: Changes in wandering behavior were not generally related to gender, age, or time since onset of dementia. Onset of different types of wandering behavior showed some relationship with cognitive state. Various forms of increased walking first appeared during moderate dementia, each type typically persisting for 1 to 2 years. Late dementia was characterized by decreased walking and immobility. Conclusions: Wandering behavior in dementia can cause great problems for carers. There are different causes for such changes, some of which are related to cognitive ability, for example increased confusion results in ineffectual “pottering” and getting lost. Increased walking at night corresponds with disruption of diurnal rhythm.