A dementia quiz was developed to assess carers' and professionals' knowledge about dementia, services needed by dementia sufferers and their families, and methods of coping with some of the problems presented by people with dementia. The quiz was compared with a UK version of Dieckmann, Zarit, Zarit & Gatz's (1988) Alzheimer's Disease Knowledge Test, one of only two published tests assessing knowledge about dementia. Both measures were given to samples of carers and professionals who were either members or non-members of Alzheimer's Disease Society. The responses were analysed to determine the reliability and validity of the new Dementia Quiz. The results were encouraging and the quiz should prove useful in teaching, clinical and research settings.