Pleural involvement is frequently seen among patients hospitalized in Intensive Care Units (ICU). In most cases, patients are hospitalized with or will develop scarce transsudative effusion secondary to cardiac failure or atelectasis. Other pleural issues in ICU concern pneumothorax in ventilated patients (barotrauma), empyema following nosocomial pneumonia or investigation procedures. More rarely hemo(pneumo)thorax or chylothorax will be diagnosed. As a rule, acute pleural pathologies rarely justify hospitalization in the ICU, depending on the etiologic mechanism or concomittant clinical signs of intolerance (respiratory insufficiency, collapsus, coma...). After tube thoracostomy, most patients will be managed in the respiratory ward to monitor the drainage, to begin etiologic diagnosis and to discuss a possible surgical intervention, usually a few weeks or months after the ICU.