summary In clinical practice many instruments are available for the screening and diagnosis of cognitive disorders. Measuring instruments can also be used to assess the severity of these disorders. On the basis of the literature and the availability of Dutch translations, in cases of dementia we recommend the use of the Mini-Mental State Examination (MMSE) for screening purposes, supplemented by the clock drawing test and the Informant Questionnaire for Cognitive Decline in the Elderly (iqcode). The NeuroPsychiatric Inventory (NPI) is recommended for behavioural and psychological symptoms in dementia, the Cornell Scale for Depression in Dementia (CSDD) for depressed dementia patients, the Cohen-Mansfield Agitation Inventory (CMAI) for agitation in dementia patients, and the Cambridge Mental Disorders of the Elderly Examination revised (CAMDEX-R) for more detailed diagnosis. For delirium patients we recommend that the Delirium Observatie Screenings schaal (DOS) be used for screening and the Delirium Rating Scale revised (DRS-R-98) for severity assessment.