We report a 24-month-follow-up study of argon plasma coagulation of the inferior turbinate (APC) in patients with perennial nasal allergy. This was a retrospective study, in which 41 patients with perennial allergic rhinitis were treated by inferior turbinate reduction using APC. The grades of nasal stuffiness, rhinorrhea, sneezing and the daily activity impairment caused by these nasal symptoms were evaluated before and then 6, 9, 12, 15, 18, 21, and 24 months after APC, using a questionnaire graded on a four-point scale according to the Severity Criteria of Symptoms of Nasal Allergy issued by the Japanese Society of Allergology. Both nasal stuffiness and any daily activity impairment significantly improved 6 months after APC. Twenty four months after APC, 8/10 (80%) of the patients reported mild or no stuffiness and 9/10 (90%) of the patients reported mild or no daily activity impairement. Neither rhinorrhea nor sneezing were significantly improved during this study. Of the 41 patients 18 (43.9%) received no additional treatment. A second APC treatment was administered to 10/41 (24.4%) patients during follow-up period. Additional conservative medications were needed in 15/41 (36.6%) patients. Among the patients uncontrolled by conservative medical treatment, inferior turbinate reduction using APC provides significant relief in a 24-month-follow-up from nasal stuffiness and daily activity impairment.