Experimental research conducted on normal subjects and on perennial rhinitis sufferers demonstrates that the application of metacholine stimulates nasal secretions and that this effect is inhibited by pretreatment with ipratropium bromide. Using the Baroody et al. method, a group of 20 healthy volunteers was used to check the effect metacholine and ipratropium/metacholine had on nasal secretions. At the same time a study was performed to determine whether these treatments modify other nasal functions: turbinate blood flow, nasal resistance, mucociliar transport. The data confirm earlier observations regarding the effect of metacholine and ipratropium on nasal secretions. A parallel effect is also seen in mucociliary transport time, most likely linked to modifications in the rheological characteristics of the mucous. On the other hand, no significant difference was found in the other functions studied: turbinate blood flow and nasal resistance. We can consider metacholine and ipratropium selective and specific, acting on the secretory function of the nasal mucosa.