Objective: External beam radiotherapy (EBRT) is frequently used to improve disease control for pediatric brain tumor patients. However, to facilitate the radiotherapy (RT) procedure, "forced" type interventions including conscious sedation or general anesthesia are frequently used to manage patients' fear and anxiety. The aim of this study was to investigate the effects of therapeutic play (TP) in reducing anxiety for pediatric brain tumor patients treated by EBRT. Methods: Between April 1st and September 30th, 2009, 19 young brain tumor patients, aged 3-15 years and recommended for RT, were recruited: ten to a control group and nine to the study intervention group. The study group was introduced with TP during EBRT. The Beck Youth Anxiety Inventory and the Faces Anxiety Scale were used to evaluate patients' psychological levels of anxiety. The heart rate variability and salivary cortisol concentrations were used to indicate the patients' physical levels of anxiety. Both the psychological and physiological tests were administered to all subjects before and after the RT procedure. Results: The study group had significantly lower anxiety scores and expressed fewer negative emotions than did the control group before EBRT. Conclusions: TP can not only improve the quality of medical services but can also reduce costs and staffing demands. In addition, it can help lower young patients' anxiety and fear during medical procedures. As a result, it further decreases the potential negative impacts of hospitalization on these young patients.