Objective: This research was carried out to study rhinomanometrically the nasal airflow in cases of deviated nasal septum linked with inferior turbinate hypertrophy. It also compared rhinomanometric improvement following surgery on nasal septoplasty and coblation associated with inferior turbinate reduction. Materials and methods: A descriptive cross-sectional method was used from January 2017 to September 2017 at ENT Hospital in Ho Chi Minh City, Vietnam. The study included 42 patients who underwent nasal septoplasty and coblation inferior turbinate reduction. The patients were interviewed and observations were noted down in SNOT-22 questionnaires. Rhinomanometry was used to carry out the assessments of preoperative and postoperative nasal airflow. Results: The total number of patients was 42, including 31 males and 11 females, and their average age was 33.56 ± 11.59 years. The preoperative assessment results show that the SNOT-22 mean score was 6.38 ± 3.10, the nasal airflow value was 461.17 ± 110.84 cm3/s, and its resistance value was 0.35 ± 0.07 Pa/cm3/s. The postoperative assessment results indicate that the SNOT- 22 mean score was 1.78 ± 1.66, the nasal airflow value was 977.26 ± 155.84 cm3/s, and its resistance value was 0.16 ± 0.03 Pa/cm3/s. The results suggest that nasal airflow and resistance improved by 2.12 and 2.18 times, respectively. Conclusion: Rhinomanometry is an objective, reliable and useful method to evaluate preoperative and postoperative nasal obstruction condition of patients. It should be used as a routine assessment instrument for patients who are selected for operation.