Pneumonia is a common cause of death in elderly people. A series of our studies have demonstrated that pneumonia in the elderly is characterized by silent aspiration, impaired swallowing and cough reflex, partly due to cerebral infarctions at basal ganglia. These infarctions probably induce the disruption of the specific central neurotransmitter system including dopamine and substance P, which plays an important role for swallowing and cough reflex. Use of ACE inhibitor and stimulation of the oral cavity by simple oral care, which are effective in increasing substance P. reduced the incidence of aspiration pneumonia. Moreover, use of a dopamine agonist such as amantadine hydrochloride and a folic acid supplement that are known to potentiate dopaminergic neurons also prevented aspiration pneumonia. For patients bedridden due to lowered ADL, it is essential for them to keep an upright position a few hours after meals to prevent aspiration pneumonia caused by the reflux of ingested foods. Also, administration of neuroleptics may cause aspiration pneumonia by suppression of dopaminergic neurons.