A study has been undertaken to compare the sensitivity of manometric rhinometry, rhinomanometry, nasal peak flow and acoustic rhinometry to detect the decongestant effect of xylometazoline. Twenty healthy volunteers were investigated before and after decongestion. The sensitivity of all four methods varied from 80 to 95%. These differences were not significant. Manometric rhinometry, a new method of investigating nasal physiology, is as sensitive as more established methods.