Total nasal resistance to airflow was measured in thirty-one subjects before and after five minutes' exposure to menthol vapour. Menthol inhalation had no consistent effect on nasal resistance but the majority of subjects reported an increased sensation of nasal airflow and a cooling effect of menthol. The results indicate that menthol stimulates cold receptors in the nasal mucosa to create an increased sensation of airflow. No evidence was found in support of any nasal decongestant action for menthol.