Although senile dementia of Alzheimer type (SDAT) is the commonest cause of dementia in the elderly, it is important to recognise potentially reversible causes such as normal pressure hydrocephalus. This has been reported to occur in association with Paget’s disease of the skull, but would appear to be an extremely rare complication of this disease. To date 4 cases of successful surgical intervention in normal pressure hydrocephalus complicating Paget’s disease of skull have been reported. We report 3 cases which have presented to one Department of Geriatric Medicine during a 3-year period. Two cases were diagnosed prior to death and both responded well to ventriculo-peritoneal shunting.