Recently the number of adolescents undergoing adenoidectomy has increased in our practice. Therefore, we were to investigate the change of age on adenoidectomy patients for 10 years (1984. 3~1993. 2). A retrospective study was done on 466 patients who underwent adenoidectomy due to adenoid vegetation. The number of patients undergoing adenoidectomy was decreased after 1990. The median age was between 7 and 8 years old and the mean age of study population as 7.38 years old. The mean age was not changed significantly through the years in the number and proportion of patients above and below the madian. As the distribution of the study population in 4 groups according to quartiles, the significant change was not noted among the groups. In summary, the mean age of adenoidectomy patients was not changed significantly through 10 years but the mean age after 1990 revealed decreasing tendency. The mean age was higher than western one. The further prospective study including ventilating tube insertion patients due to adenoid vegetation will be needed especially after 1990.