The aim of this paper is to present toxic effects of aluminium on the nervous system. This metal belongs to environmental factors that may play a crucial role in the pathogenesis Alzheimer's disease (AD). The molecular mechanism of AD may consist in P-amyloid accumulation in the presence of aluminium, leading consequently to neurodegeneration. P-amyloid causes an abnormally high concentration of Ca²+ ions in neurons resulting in neurodegenerative changes. The cholinergic system, and especially hippocampus and cortex are known to be particularly affected in AD. The amount of Aluminium absorbed from food and drugs in the gastrointestinal tract, transported into and accumulated in the brain is crucial for human health. The daily consumption of aluminium ranges from l0 to 40 mg. A small amount of Aluminium (approximately less than l%) is absorbed from food via the gastrointestinal pathway. A relatively small proportion of this dose gets through the blood-brain barrier and enters the brain. However, the ability of the brain to eliminate aluminium is limited and therefore, Aluminium accumulates in the brain in an age-dependent manner. Some epidemiological studies show a relationship between concentration of aluminium in the drinking water and Alzheimer's disease.