A 17-year-old girl presented with recurrent episodes of pneumonia related to localized bronchiectasis in the lingula. On computed tomography and magnetic resonance imaging, the cause of this was found to be an inwardly projecting exostosis arising from the left fifth rib. The patient underwent thoracotomy and excision of the exostosis with the affected area of lung. We report here the unusual case of a rib exostosis presenting with localized bronchiectasis.