Nasal obstruction is predominantely a subjective patient complaint. So, there is wide variation in the patient's interpretation of the symptoms. While the history and physical examination are reasonable diagnostic indicators, an objective means of evaluation is needed. Rhinomanometry is an objective tool which measures nasal obstruction reliably. Nasal airway resistance was measured on 20 healthy persons and 29 patients with nasal obstruction before and after nasal surgery and removal of nasal secretion by active anterior rhinomanometry. The results were as follows ; 1) The mean total nasal resistance was 0.275 Pa/cm³/sec in control group and 0.420 Pa/cm³/sec in patient group. 2) After surgery the total nasal resistance of patient group after epinephrine was decreased from 0.313 Pa/cm³/sec to 0.237 Pa/cm³/sec. 3) There was high correlation between the nasal airway resistance and symptoms of nasal obstruction before and after nasal surgery. 4) Nasal airway resistance of patient group who had a high nasal airway resistance was decreased after removal of nasal secretion. But there were no significant changes of nasal airway resistance in control group after removal of nasal secretion. 5) We concluded that rhinomanometry could be useful in evaluation objectively the severity of nasal obstruction and the results of nasal surgery.