Widespread use of CT-scans leads to increased discovery of mediastinal and hilar lymph node enlargement, a frequent motive for consulting a pulmonologist. The persistence or progression of such lymphadenopathies outside of an oncological context is most often associated with an infectious process or inflammatory disorders. The history will also point to possible occupational or environmental exposure. The radiological characteristics specific to lymphadenopathies and any associated parenchymal lung damage will most often orient the diagnosis. Endobronchial ultrasound-guided techniques allow targeted and real-time sampling of the mediastinum and hilar lymph nodes, representing the first-line investigation before more invasive surgical procedures.