Aortotracheal fistula is a rare condition that is invariably fatal if not diagnosed and surgically treated. Patients usually present with small intermittent haemoptysis. In cases of aortotracheal fistula bronchoscopy may be both misleading and dangerous. The findings using computerized tomography (CT) are usually non-diagnostic. We present a case of aortotracheal fistula in which CT established the diagnosis by demonstrating the fistula as a continuous tract between the aorta and the trachea. CT should be considered in the initial investigation of patients suspected to have such a disease.