Cancer and its treatment are generally considered to be stressful. One of the important approaches used to reduce the anxiety is therapeutic music. The purpose of this study was to examine the effects of therapeutic music on anxiety in children with ALL. This study was conducted as single-grouped pre-test, post-test quasi-experimental design at the paediatric oncology unit of a university hospital in Turkey between February 2010 and June 2010. 28 children were selected by using convenience sampling. In order to obtain the study data, the VAS was used. The duration of the therapeutic music sessions ranged from 15 to 30 minutes during the chemotherapy procedure in the child's room. At the beginning and end of therapeutic music session, the child completed 0-10 point VAS. In this study, it was determined that anxiety of post-test measures decreased to pre-test measures for all age groups and the difference between them was found as statistically very significant (p<0.05). P<0.05 is a standard level of significance. The findings of this study, which are consistent with previous reports, support the opinion that therapeutic music may have a positive effect on hospitalised paediatric oncology patients.