The aim of this paper is to evaluate the efficacy of intranasal hyposensitizing therapy in perennial rhinitis. 36 patients suffering from perennial allergic rhinitis (Dermatophagoides-sensitive) underwent a double blind placebo-controlled trial for a period of 8 months. The efficacy of nasal immunotherapy was evaluated by collecting symptoms score and evaluating objective rhinological parameters (nasal resistance, cross areas and volumes, mucociliary clearance times, specific nasal provocation threshold). A significant improvement (p&#x003C0,01) of symptom score of active against placebo group was observed after treatment. Also objective nasal parameters (total nasal resistances, mucociliary clearance, C-notch area, and provocative threshold) significantly (p&#x003C0,01) improved after treatment. Adverse local reactions were rare and did not interfere with the protocol. The results underline the efficacy and quickness of local nasal immunotherapy in the treatment of perennial allergic rhinitis documented by the improvement of subjective and objective parameters.