Cerebro-spinal fluid (CSF) and blood levels of aluminium, cadmium, calcium, copper, lead, magnesium, and mercury were studied in 24 subjects with dementia of the Alzheimer type (DAT) and in 28 healthy volunteers. Furthermore, arsenic, bromine, chrome, iron, manganese, nickel, rubidium, selenium, strontium, and zinc were measured only in blood. There were significant changes in the DAT group when compared to the controls. The plasma levels of aluminium, cadmium, mercury and selenium were increased and the contents of iron and manganese were lower in the DAT group as compared to control subjects. In CSF there were low levels of cadmium and calcium and increased content of copper in DAT cases. Iron and zinc levels in blood and calcium in both blood and CSF of DAT patients correlated with memory and cognitive functions. Iron, manganese and strontium levels of DAT sufferers in blood and aluminium in CSF were related with changes in behaviour.