Bronchomalacia in adults develops secondary to bronchial disease processes (chronic bronchitis, tuberculosis, neoplasm) or to lesions resulting from prolonged intubation, surgery, trauma, or lung transplantation. We report the case of an 84-year-old woman with no history of any of the aforementioned associations in whom we detected severe idiopathic bronchomalacia of the main left bronchus. The identified lesion caused recurrent pneumonias leading to death. We show images obtained by bronchoscopy, revealing the severity of the lesion and its functional repercussions.