The Kungsholmen Project is a study on elderly people living in a parish of Stockholm, Sweden. The study uses a longitudinal approach with the principal purpose of determining the natural history of Alzheimer's disease and other dementias. The study population consists of all 2,368 inhabitants of the Kungsholmen area in Stockholm, aged 75 years and above in October, 1987. The study design consists of three phases. Phase I consists of a screening test used in order to identify the 'possible' dementia cases; phase II is a complete clinical examination carried out in order to reach a final diagnosis of dementia; in phase III the whole population is reexamined in order to ascertain new cases of dementia. DSM-IIIR criteria for dementia and different types of dementia are used. The final diagnosis is based on a consensus using two preliminary diagnoses, made separately by different physicians.