Ostial airway resistance (OAR) of 11 maxillary ostia and the airway resistance of the nasal cavity (NAR) in 6 healthy persons were tested before and after administration of phenylpropanolamine (Ppa) and placebo. The effects of physical exercise were also tested. After logarithmic transformation, the resistance values showed a normal distribution. Significant effects on the ostial resistance in relation to initial values were found after Ppa medication. The effect was more pronounced in recumbency than in the sitting position. Physical exercise also gave a significant reduction of ostial resistance while placebo treatment was without effect. On comparison of the Ppa- and placebo-groups in an extended statistical analysis, more striking differences were found both for OAR and NAR. In this model study, Ppa thus showed effects in healthy individuals.