Probands (n = 3607) living in long-term care institutions in the county of Västerbotten were assessed to estimate whether the prevalence of dementia in different types of institutions had changed since a similar survey was made 7 years before. The probands' motoric functions, vision, hearing, speech, prevalence of behavioral disturbances and psychiatric symptoms, work load and use of psychoactive drugs were also investigated with special emphasis on the differences between the demented and the non-demented. About 40% were demented. This proportion of demented patients had increased in somatic long-stay clinics, nursing homes and homes for the aged since 1975. Further, the mean age of the probands and their length of stay had increased in these institutions. Demented probands were more impaired with regard to motor functions, speech, vision, hearing, ADL-functions, behavioral and psychiatric symptoms, and they also imposed a higher work load on the staff than the non-demented. Demented probands were also prescribed psychoactive drugs, i.e. neuroleptics but not minor tranquilizers or antidepressants, more often than the non-demented in accordance with the increased prevalence of behavioral disturbances and psychiatric symptoms.