A 60-year-old woman presented with dyspnoea and respirophasic chest discomfort, as well as a history of idiopathic oesophageal diverticulum. Physical examinations showed no evidence of Ono's sign, fever and weight loss. Chest radiograph revealed a right-sided transudative pleural effusion. Barium oesophagogram made a diagnosis of acquired esophagobronchial fistula communicating between oesophagus and bronchus. The oesophagobronchial fistula, causing pleural effusions, was very small and could be caused by idiopathic oesophageal diverticulum. The pleural effusion was removed by thoracentesis, which improved her symptoms. Surgical therapy or covered oesophageal stenting was advised, but she declined. She is followed-up regularly on an outpatient basis.