Objective: To explore the phenomenology and prevalence of Self-Injurious Behaviour (SIB) in nursing home patients with dementia. Method: Cross-sectional study of 110 nursing home patients with dementia. Nurses' ratings of SIB and other behavioural disturbances were compared to independent resident physician ratings of medical charts data pertaining to dementia type, dementia severity, prescribed psychotropic drugs, immobility and measures to restrain the patient. Instruments used were the Overt Aggression Scale (OAS, modified), Behaviour Rating Scale for Psychogeriatric Inpatients (GIP), Rating scale for Older Patients (BOP). Results: SIB was observed in 22% of the dementia patients. Pinching or scratching oneself and banging one's fist against objects were most frequently reported. Five patients showed a combination of two types of SIB. As expected, SIB was modestly related to Aimless repetitive behaviour and Aggression and no association was found between SIB and Apathy. Correlates of SIB were prescribed psychotropics (i.e. benzodiazepines), immobility and measures to restrain the patient. Conclusions: Preliminary data suggest that SIB is a specific psychopathological phenomenon that is highly prevalent in nursing home patients with dementia. Future research should focus on the aetiology and treatment of SIB. Copyright © 2005 John Wiley & Sons, Ltd.