Nasal obstruction, triggered by allergic rhinitis, often does not resolve with allergen-specific immunotherapy (AIT) alone, thus inferior turbinate reduction surgery (ITR) may be required. This study aims to investigate the impact of combined treatment on nasal obstruction, as evidence is currently limited. A retrospective cohort study of perennial allergic rhinitis patients experiencing nasal obstruction and undergoing ≥12 months AIT was conducted. Two groups were derived, those undergoing AIT-with or without an ITR. Patient reported nasal obstruction (evaluated with questionnaires) and nasal airway function (Nasal Peak Inspiratory Flow [NPIF] and Nasal Airflow Resistance [NAR]) were monitored. The change from baseline to 12 months post-treatment in each group were compared. A total of 118 patients (33.71 ± 14.43 years, 41.5% female) were recruited, 72% had AIT and 28% AIT&ITR. At baseline, the AIT&ITR group had a higher level of nasal obstruction (>moderate%; 63.6% vs 52.9%, P = .048). Post treatment, AIT&ITR group reported greater reduction in nasal obstruction (>1 category change: 75.8% vs 48.2%, P = .002). Similarly, the AIT&ITR group had greater improvement in nasal function by NPIF (-13.9 ± 110.3 L/minute vs -3.4 ± 78.1 L/minute, P = .049) and NAR (-0.120 ± 0.342 Pa/cm³/second vs -0.093 ± 0.224 Pa/cm³/second, P = .050). Allergic rhinitis patients, with moderate to severe nasal obstruction, who undergo combined AIT&ITR have greater relief of nasal obstruction and improved airflow analysis compared to AIT alone.