The Cambridge Behavioural Inventory (CBI) is a short, self‐administered informant questionnaire developed to distinguish between the behavioural and psychiatric symptoms of Alzheimer's dementia and fronto‐temporal dementia. Here, Dr Hancock and Dr Larner present the results of their study to investigate the diagnostic utility of the Cambridge Behavioural Inventory in a cohort of patients attending their memory clinic. Copyright © 2008 Wiley Interface Ltd