In order to investigate the effect of the nasopulmonary reflex on the regulation of airway resistance, the nasal mucosa was stimulated with white pepper powder and the change in airway resistance was evaluated in 13 totally laryngectomized patients and 39 normal subjects. The results were then analyzed to clarify whether there was any difference in the pattern of the change in airway resistance between the two groups. In totally laryngectomized patients, airway resistance often diminished significantly after stimulation. In normal subjects, on the other hand, a significant increase in airway resistance was often observed. The above results suggest that stimulation of the mucosa of the upper airway causes dilation of the trachea and bronchi accompanied by a decrease in airway resistance in laryngectomized patients. The stimulation presumably dilates the trachea and bronchi in normal subjects as well, but the effect of the dilation appears to be overpowered by the constriction of the larynx and, as a result, an increase in airway resistance is observed. 4