Given the conflicting evidence regarding adenotonsillectomy and the risk of upper airway infections (UAIs), including acute pharyngitis (APT), rhinosinusitis (ARS), and otitis media (AOM), we evaluated the risk of developing UAIs following adenotonsillectomy in a childhood population. In this population-based follow-up study, we used data from the National Health Insurance Service-National Sample Cohort. The adenotonsillectomy group (n = 2,377) included patients aged <10 years who underwent an adenotonsillectomy. For every patient with APT (n = 2,309), ARS (n = 2,308), and AOM (n = 2,207) who had an adenotonsillectomy, four participants were randomly selected for the control groups (n = 9,204, n = 9,196, and n = 8,788, respectively) using propensity score matching. The number of postoperative hospital visits for UAIs was recorded for 1 to 9 years, and the equivalence test was used to compare the number of visits between the adenotonsillectomy and control groups. There were no significant differences in the incidence of APT, ARS, or AOM at the margin of equivalence of difference (-0.5 < 95% confidence interval of difference < 0.5) between the two groups from postoperative year 1 to year 9. The hospital visits for these diseases gradually decreased over time in both groups. There was a significant decrease in the number of visits for APT, ARS, and AOM in the 5-9 years age group when compared with those in the <4 years age group (P < .01). Our results suggest that adenotonsillectomy does not alter the frequency of UAIs in children. NA Laryngoscope, 131:2376-2383, 2021.