This chapter discusses the diagnosis, evaluation and management of pneumonia. Typical pneumonia presents with a sudden onset of fever and chills accompanied by productive cough with purulent sputum. It may also be accompanied by pleuritic chest pain and dyspnea. It is traditionally caused by Streptococcus pneumoniae, and Haemophilus infuenzae. All patients with AIDS who have pneumonia should be placed in respiratory isolation because the chest radiograph cannot discriminate between bacterial pneumonia and tuberculosis. Two clinical decision rules can assist the physician in deciding whether a patient needs to be admitted for inpatient management, or can be discharged home with outpatient follow-up. Patients' ability to oxygenate and ventilate can decompensate rapidly. If this occurs, intubation and mechanical ventilation will be required. Patients presenting with pneumonia whose blood pressure is deteriorating should be treated as septic shock. Norepinephrine is the first-line vasopressor for this condition.