Objective: This study investigated the early and late postoperative maximal bite force (MBF) values in pre-pubertal children undergoing adenotonsillectomy (AT) and compared them with healthy control. Methods: A total of children aged 6-12 years, diagnosed with chronic obstructive adenotonsillar hypertrophy (COATH), undergoing AT (n=30), and healthy controls (n=30) were included. The MBF and body mass index (BMI) were recorded for up to sixth months. The duration of active surgery was recorded. The visual analog scale (VAS) was applied to the patients for the pain on postoperative first and seventh days. Results: There was no significant difference in MBF values between the groups from the baseline to sixth month (p>0.05). A statistically strong positive correlation was observed between MBF and age (p<0.05). A significant difference was observed in MBF changes in patients with duratşon of active surgery more than 20 min compared with those with less from the baseline to the first month (p<0.05). In the study group, it was observed that there was a low and moderate correlation in the mean changes between the MBF and BMI in the first, 7th day, and 1st-month matches (p<0.05). The VAS scores did not show a significant correlation with the MBF values (p>0.05). Conclusion: The COATH and sex did not have a significant effect on MBF in pre-pubertal children, but age did. The postoperative MBF values were reached in the 1st month almost baseline values and there was a rapid increase between three and six months after AT. The prolonged operative time may affect MBF during one month postoperatively.