Total nasal resistance was measured in 42 white caucasian and 32 black healthy adults by both anterior and posterior rhinomanometry after using a nasal decongestant. The nasal airway resistance was found to be lower in the blacks compared to the caucasians by both anterior and posterior methods. The mean total nasal airway resistance was 0.136 Pa/ cm3/s in the blacks and 0.179 Pa/cm3/s in the caucasians by the anterior method, and 0.134 Pa/cm3/s and 0.161 Pa/cm3/s, respectively, by the posterior method. These differences were highly statistically significant.