The aim of the present study was to demonstrate the therapeutic effect sulphurous-arsenical-ferruginous waters from had on aspecific phlogosis of the upper respiratory tract (URT). This double-blind study involved treating 37 adults of both sexes with sulphurous-arsenical-ferrignous water (group A) and another 14 subjects, again suffering from the same aspecific, chronic catarrhal disorder and selected with the same criteria, with the aerosol vapor inhalation of drinking water from the city mains (group B). All subjects included in the study underwent the following tests both before and after the cycle of crenotherapy: Objective E.N.T. examination Anterior Active Computerized Rhinomanometry (AACR) Mucociliary transport time (MTT) Nasal cytology Physical and immunochemical examination of the nasal mucous. The post crenotherapy variations achieved indicate that the sulphurous-ferruginous waters have a beneficial therapeutic effect: indeed, the mucosa was able to perform its complex functions, particularly specific and aspecific defense of the organism. In fact, among other things, group A showed decreased resistance and increased nasal respiratory flow, normalized of mucociliary transport, decreased bacterial layer and increased plasma cells in the rhinocytogram, and an increase in albumin, non secretory immunoglobulin and the secretory portion of secretory immunoglobulin A in the nasal mucosa. None of these variations--many of which were statistically significant--were seen in the controls group treated with drinking water from the public mains.