A 19-year-old female with a 3-day history of high temperature, productive cough and dyspnoea was admitted due to diabetic ketoacidosis and pneumonia of the right lower lobe. Antibiotics (amoxicillin-clavulanic acid), insulin, fluids and electrolytes were administered, as appropriate. The patient was doing well (normal temperature, normal glucose levels, normal acid-base balance) until the sixth day of hospitalization, when she reported bouts of cough when swallowing liquids. Barium oesophagography revealed the presence of a broncho-oesophageal fistula (BOF). Congenital BOFs are rare developmental malformations (only just over 100 reported cases in the literature), which are attributable to persistent attachments between the tracheobronchial tree and the oesophagus. When not combined with oesophageal atresia, symptoms may not appear until adult life. History of recurrent respiratory infections, bronchiectasis, haemoptysis and chronic cough associated with eating, may indicate investigation with conventional or multi-positional oesophagography. At the time that surgery was decided, our patient developed persistent pneumonia of both the middle and the lower right lobes. A fistulous tract between the medial segmental bronchus and the oesophagus was removed, along with right middle lobectomy. Post-operative clinical course was excellent.