The aim of this study was to develop a test for the measurement of nasal reactivity. Different concentrations of methacholine were sprayed intranasally, and the nasal secretion and blockage were measured in normal subjects. The simple collection and measurement of secretion was found to be a valuable parameter of mucosal reactivity, while measurement of nasal airway resistance was unreliable, due in part to the presence of secretion in the nasal cavity. The methacholine test had a fairly good reproducibility when the amount of secretion was used as the only parameter. It caused a significantly stronger reaction in women than in men. Patients with perennial rhinitis had a more vigorous response than the controls. It is concluded that the methacholine test may prove useful as a sign of perennial rhinitis and also for the objective evaluation of medication, but further studies are warranted.