Abstract : Endobronchial ultrasound (EBUS) is a minimally invasive investigation method that permits transbronchial needle aspiration (TBNA) of mediastinal and hilar lymphadenopathies in order to determine their etiology. Its indications are notably lung cancer staging and lymphadenopathy exploration in case of sarcoidosis and malignant lymphomas. The employment of EBUS-TBNA has grown over the past few years and has become an alternative to mediastinoscopy due to a lower complication rate. However, in rare cases, complications can occur as hemorrhage, infections (mediastinitis, pneumonia, pericarditis, cyst infection, sepsis) or other (pneumothorax, pneumomediastinitis). We report herein a case of a mediastinitis after endobronchial ultrasound-guided transbronchial needle aspiration which occurred in a 63-year-old patient treated by methotrexate and methylprednisolone for a rheumatoid arthritis. The symptoms appeared as fever and progressive dyspnea some days after the endoscopic procedure.