Diseases of the lung are one of the main causes of morbidity and mortality in the elderly. The risk of respiratory infections is increased due to structural changes, malnutrition, co-morbidity, and a variety of other factors. Bacterial and viral pathogens cause acute bronchitis and exacerbations of chronic bronchitis (AECB). Community acquired pneumonias (CAP) show a different spectrum of pathogens and clinical course in comparison to nosocomial pneumonias (hospital acquired pneumonia, HAP). Institutionalised patients are at risk of a health care associated pneumonia (HCAP), with often a different spectrum of pathogens in comparison to CAP and HAP. Elderly patients with cerebrovascular disease and impairment of swallowing or cough reflexes often suffer from aspiration pneumonias. The mortality is highest in the elderly, comorbid, and immunocompromised patient with nosocomial pneumonia. Important preventive measures include influenza and pneumococcal vaccination, avoidance of immobility, oral hygiene, and sufficient nutrition.