Pulmonary involvement in Behçet's disease is not usual, and the occurrence of spontaneous pneumothorax is evena rarer complication. We report the case of a secondary spontaneous pneumothorax occurring in a patient aged 21 diagnosed of Hughes-Stovin syndrome treated with colchicine, corticosteroids and cyclophosphamide. The patient experienced chest pain with acute dyspnea. The examination found an increase in the sonority during percussion of the thorax with a decrease in respiratory sounds in auscultation. Chest X-ray and thoracic CT scan showed the presence of a left medium-sized pneumothorax that extended rapidly and became bilateral. The patient was transferred to a resuscitation unit undergoing a chest drainage. The course was marked by severe respiratory distress requiring intubation. The pneumothorax was probably caused by the rupture of pneumatocele in the pleural cavity. Several factors have contributed to pneumatocele formation, including pulmonary pneumonitis and mechanical ventilation in a lung already weakened by the inflammatory process of Behçet's vasculitis.The patient had died with an unexplained etiology.