Background: Cancer disease causes children with psychological disorders such as anxiety and depression to reduce their need for appropriate psychological treatments such as child-centered mindfulness treatment for depression and anxiety. Aims: Therefore, the objective of the present study was to investigate child-centered mindfulness therapy on the depression and anxiety after drug therapy in the children with cancer. Method: The research method was quasi-experimental with pretest, posttest, control group and two-month follow-up design. The statistical population of the present study included all the children with cancer in 2018 in the city of Isfahan who referred to Omid therapy center and received drug therapy. The sample size was 30 children with cancer who were selected through convenient sampling method and randomly replaced into experimental and control group. The experimental group received 60-minute therapeutic interventions related to child-centered mindfulness (Burdic, 2017). during two-an-a-half months once a week. The applied instruments included child depression questionnaire (Quax, 1992) and children anxiety multi-dimensional scale (March, et.al, 1997). The data analysis was conducted through descriptive statistics and repeated measurement ANOVA. Results: The results showed that child-centered mindfulness therapy has significantly influenced the depression and anxiety after drug therapy of the children with cancer (p<0/001) in a way that this treatment was able to decrease depression and anxiety of the children with cancer. Conclusion: According to the findings of the present study it can be concluded that mindfulness therapy can be used as an efficient treatment to decrease the children’s depression and anxiety in the children with cancer through employing techniques such as thoughts, emotions and mindful behavior.