Neuro-toxic effects of aluminium, with disorders mainly in motor coordination, have been proved in epidemiological studies of subjects professionally exposed to aluminium. However, there is, as yet, no adequate evidence that neurotoxicity of aluminium leads to progressive dementia and Alzheimer's disease. It is likely that long-term use of drinking water with a high aluminium concentration, with pH about or less than 7.0, and with low fluoride concentration, is associated with the increased relative risk of Alzheimer's disease. The use of aluminium-containing antiacids, antiperspirants and beverages from aluminium cans, are probably of small importance concerning Alzheimer's disease. The relation of aluminium cumulated in the brain to onset of Alzheimer's disease is still unclear, as neuro-pathological lesions, which can be noticed in acute dementia caused with aluminium, significantly differ from those in Alzheimer's disease. Furthermore, morphological and biochemical characteristics of neurofibrillary tangles which occur in the brain after experimental injection of aluminium are different from the tangles in Alzheimer's disease. Results of the studies concerning aluminium concentrations in the brain of patients with Alzheimer's disease are incoherent. To resolve this scientific problem it is necessary to follow-up the prognosis of neurotoxic disorders caused by aluminium. It should be clarified as well whether aluminium in neuro-pathological findings of Alzheimer's disease is an artefact caused by alumino-silicates present in most reagents for tissue-staining.