Mounier-Kuhn syndrome (tracheobronchomegaly) is a rare disorder characterized by pathological dilation of the trachea and bronchi, tracheal diverticulosis, and recurrent respiratory tract infections. First described by Mounier-Kuhn in 1932, the syndrome arises from connective tissue and smooth muscle atrophy within the large airways, leading to impaired airway stability and mucociliary clearance [1]. Consequently, patients experience recurrent pneumonia, bronchiectasis, and progressive respiratory failure. While anesthetic management strategies, such as supraglottic airway use, are frequently discussed [2], invasive mechanical ventilation (IMV) data in intensive care unit (ICU) settings remain scarce [3,4]. In this report, we present a case of Mounier-Kuhn syndrome complicated by acute respiratory distress syndrome (ARDS) secondary to pneumonia, in which high-frequency jet ventilation (HFJV) was utilized as salvage therapy in the ICU.