Pneumonia is the leading cause of death due to infectious disease in the elderly and the fourth most common cause of death overall. Streptococcus pneumoniae remains the main aetiological agent in community-acquired pneumonia. Aspiration pneumonia related to neuromuscular disease is also a frequent event. Pneumonia is the second most frequent hospital-acquired infection in long-term care facilities. For community-acquired pneumonia, initial therapy is most often empirical but invasive diagnostic tests may be required if signs of severity are present. Broad-spectrum coverage is usually required using a second- or third-generation cephalosporin and only in the case of failure are invasive investigations necessary. Aspiration pneumonia may be treated with a combination of a beta-lactam and a beta-lactamase inhibitor. Initial therapy of nosocomial infections is based upon the susceptibility pattern of bacteria identified.