The last five years have produced a large output on the epidemiology of dementia and cognitive impairment, specially on apolipoprotein E (apo E), vascular changes, and education as risk factors. Minor cognitive deficits have been studied prospectively to assess their value in predicting dementia. Reviews of work from particular centres and articles on special aspects give more detail. Preference is given to population-based over clinic-based studies and to those published in or after 1994.