Nasal patency was measured by five techniques in 24 subjects and the results compared. In addition three pulmonary parameters were measured as well as height and weight. Nasal resistance to airflow measured by active anterior rhinomanometry was found to be highly correlated with peak nasal inspiratory flow rate. Other correlations were also noted. Peak nasal inspiratory flow was itself highly correlated with pulmonary peak expiratory flow rate as well as with several other parameters. The possible reasons for these correlations are discussed in terms of fluid mechanics.