Behavioral and psychological symptoms are highly prevalent in dementia. The Neuropsychiatric Inventory was constructed to measure these symptoms. Data from three studies are presented concerning psychometric aspects of the NPI Dutch version. The NPI was compared to the Revised Memory and Behavioral Problems Checklist (RMBPC) and the Mini Mental State Examination (MMSE). In the three selected patient samples prevalence of behavioral or psychological symptoms was as high as 90%. Interrater agreement (n = 19) was very high (kappa > .90). Factor analysis (n = 199) supports NPI construct validity. The NPI items correlated reasonably high (R = .35 - .60) with the relevant RMBPC subscales (n = 24). Although some NPI items did, the NPI total score was not significantly related to the MMSE. The NPI Dutch version can be scored objectively and it is a valid rating scale for measuring a wide range of behavioral and psychological symptoms of dementia.