The upper airway respiratory diseases (i.e. common cold, allergic rhinitis, nonallergic/vasomotor rhinitis, acute and chronic rhinosinusitis and nasal polyposis) in which nasal congestion is a common symptom are often undertreated due to the frequent inadequate efficacy and safety concern with current therapies. In scientific literature, few studies seem to support the hypothesis that nasal inhalatory treatment with thermal water promotes the improvement of nasal symptoms, even if the mechanisms by which the improvement from SPA therapy can be expected remain debated. A prospective comparative study with a pre-post design has been performed consecutively enrolling 33 (males 70 %) patients of both genders older than 12 years of age, affected by chronic sinonasal inflammation. All patients underwent a 14-days course of radioactive water warm vapour inhalations followed by nasal aerosol of the same thermal water 10 min each once/day at Merano Therme. At the beginning and end of the study, in all the subjects, nasal function evaluation by active anterior rhinomanometry, mucociliary transport time (MCTt) determination and nasal cytology were performed. After the inhalatory treatment, the mucociliary function was improved and the pathologic mucociliary transport times recorded at the beginning of the study being significantly reduced to physiologic ones. Besides, before treatment, the cytologic picture showed an inflammatory cell infiltration (eosinophils, neutrophils with/without bacteria, mast cells) in 37 % of patients; after therapy in 66 % of these patients, the rhinocytogram was normal. Our results suggest, according to the literature data, that SPA therapy with radioactive water could represent an alternative choice in chronic inflammatory diseases of the upper airways, nonresponsive to pharmacological therapy.