Chest X-ray in a 17-year-old boy, presenting with haemoptysis, revealed a radiopaque foreign body (FB) in the right lower lobe. There was no history of aspiration. CT located the needle-shaped FB in the right posterobasal lower lobe segment bronchus. In bronchoscopy, the FB turned out to be a pin, of which the radiolucent plastic head was embedded in the peribronchial tissue. Extraction by flexible and rigid bronchoscopy failed; finally, thoracotomy and bronchotomy had to be performed to remove the pin. In delayed diagnosis of a tracheobronchial FB, CT scan is not only necessary to localise the FB but also to depict or rule out secondary pulmonary changes. Nevertheless, radiolucent components of a metallic FB might be invisible even in CT, leading to underestimation of its size and extension. Late diagnosis complicates removal of tracheobronchial foreign bodies and may even necessitate open surgery, including pulmonary resections.