Background: Children with brain tumors experience potential neurologic complications when are treated with radiotherapy, especially if done frequently under anesthesia. Objectives: This study aimed to evaluate the neurologic complications associated with anesthesia in pediatrics treated with radiotherapy under anesthesia. Methods: This cross-sectional study consisted of 133 pediatric patients with a brain tumor who needed anesthesia for performing radiotherapy and were referred to Omid Charity Hospital and Imam Khomeini University Hospital from 2014 to 2020 by the census. Statistical values less than 0.05 were considered significant (P < 0.05). Results: The patients were in range of 1 - 8 years, and the number of 3,208 anesthesia inductions were conducted for daily radiotherapy. Major complications such as stroke, arrhythmia, tachyphylaxis, and aspiration were not observed. There was a significant relationship between the tumor side, anesthesia, and neurologic complications (P < 0.05). No significant differences were found between demographic data (age, sex, and weight) (P > 0.05). Conclusions: Anesthesia complications in this study were slight and insignificant. Some were either due to the tumor effect on other vital organs or prior exposure to radiotherapy and chemotherapy. Thus, for providing safe anesthesia, considering the tumor effect on body organs and neurologic complications caused by it can be a great help to reduce anesthesia complications in pediatrics under radiotherapy.