This paper reports on research that illuminates how people with a learning disability understand dementia and indicates the implications of these understandings for developing appropriate models of care. As this new policy and practice area struggles to provide appropriate and effective models of care for people with a learning disability and dementia, an awareness of service users' understandings of dementia leads to a number of important insights. The wider research programme from which this paper is drawn aims to identify best practice in supporting people with learning disabilities to stay in their own homes as they grow older and develop dementia. A combination of focus groups, ethnography and individual interviews were conducted at eight sites across England. Participants were people with a learning disability who had dementia, and those who have lived with someone with dementia. The findings have the potential to improve support to this population as they grow older.