Although music therapy is well documented in medical settings, the effects of the music therapy has not been well established yet. This study aimed to investigate the effectiveness of the music therapy on anxiety, and pain symptoms of children with cancer. Participants (aged ranged 6-16) were randomly allocated to one of two music therapy groups: 1) earphones with classical music, no choice (n = 20) or 2) earphones with classical music, free choice (n = 20) and a control group (n = 20) (earphones without music). In all groups, children listened to music (or the white noise) for 10 minutes before the chemotherapy. All of the symptoms were measured before the music therapy, during the chemotherapy (after the music therapy), and after the chemotherapy. State Trait Anxiety Inventory for Children (STAI-C), and Wong-Baker Faces Pain Rating Scale was used to measure the anxiety, and pain scores of the children. One-Way ANOVA and Mixed ANOVA analysis were used to analyse the effectiveness of the music. Results showed that the anxiety level of children decreased significantly in the music groups during and after the chemotherapy. However, music therapy did not affect the pain level of children