The study of the effects of oral administration of aluminium chloride on the Hippocampus of wistar rats was designed in order to ascertain whether the small daily amount of aluminium that gain access to the body produce any damage to the hippocampus. This investigation was carried out using 50 female adult wistar rats.The animals were divided into five groups; 10 rats per group (cage). Stock solution of aluminium chloride was prepared (2 g/L or 2 mg/mL). Different concentrations of aluminium were administered to different groups orally. Group I was control, while Groups II-V were given 0.4, 1, 2, and 3 mg, respectively per each rat with an average weight of between 150-200 g for duration of twelve (12) weeks. The animals were humanly sacrificed using chloroform and then the brain tissues were fixed immediately in Bouin’s fluid. The brain sections (hippocampus) were processed through the routine tissue processor. The stained samples were examined by means of light microscope for histological changes. Histological examinations showed clumpy of cell neurons, or reduced pyramidal cells and scant,y neurofibrillary tangle which was an indication of neurodegeneration in the treated groups when compared to the control. It was however, concluded that the oral administration of aluminium chloride could induce brain damage which may impair memory and learning as seen in Alzheimer disease.