Tracheobronchomegaly, first described in 1932 by Mounier-Kuhn, is a well-known clinical and radiological entity characterized by marked weakness of the trachea. It can be congenital or acquired. Some well-known inflammatory and infectious conditions have been associated with the acquired form. Endotracheal intubation can traumatize the trachea and usually results in focal stenosis, but may infrequently cause focal tracheobronchomegaly. It is not clearly understood why some cases result in stenosis and others in dilatation. This study reports the case of a patient whose clinical course was complicated by the development of intrathoracic focal tracheobronchomegaly during mechanical ventilation.