Pneumonia ranks as the third leading cause of death in Japan. About 97% of patients who die because of pneumonia are elderly, with aspiration generally thought to be involved in the majority of cases of pneumonia in elderly. Once an elderly individual contracts pneumonia, their physical function often declines and their activities of daily living diminish with hospital admission, even in individuals with no underlying disorders. Prolonged confinement to a bed and immobility leads to weakening of the legs and back, making it difficult for elderly patients to attend daily outpatient clinics, often leading to admission to nursing facilities for the aged instead of returning to their own home, even after curative treatment for pneumonia. Most such patients repeatedly develop pneumonia and repeated antibiotic treatment enhances the risk of the emergence of resistant organisms. It is beyond doubt, therefore, that prevention of pneumonia is of vital importance in the elderly.