A 50-year-old man with pulmonary fibrosis and COPD presented with worsening cough, dyspnea, chest pain, and hypoxemia of no readily apparent etiology, approximately four weeks after insertion of a transtracheal oxygen therapy catheter. Despite vigorous bronchial hygiene therapy, the patient died. Autopsy revealed obstruction of the trachea by a large mucous ball. We point out the nonspecificity of physical and radiologic findings associated with this condition and suggest that serial flow-volume loop analysis or earlier use of fiberoptic bronchoscopy might have been of assistance in premortem diagnosis of the mucous plug.