Cancer is one of the chronic diseases and one of the main causes of death in children. The aim of the present research was to determine the effectiveness of attention-based cognitive rehabilitation on anxiety and executive functions of children with leukemia after chemotherapy. This research was applied and semi-experimental with a pretest-posttest design with a control group. The statistical population included all children between the ages of 7 and 12 with leukemia in Ahvaz, among whom 30 people were selected as the research sample and randomly divided into two experimental (15 people) and control (15 people) groups. They responded to Spence Children’s Anxiety Scale (SCAS), child version (1997), Spence Children's Anxiety Scale–Parent (SCAS-Parent) (1999) and the Behavior Rating Inventory of Executive Function (BRIEF) Gioia et al. (2000). Then the experimental group received 10 sessions of attention-based cognitive rehabilitation intervention individually. Multivariate covariance test and SPSS software, version 26, were used to analyze the obtained data. The findings showed 78% changes in separation anxiety, 69% changes in social anxiety, 46% changes in mental-practical obsession, 68% changes in panic-market phobia, 67% changes in general anxiety, and 51% changes in children's fear of physical injuries from the difference between experimental and control groups arose. Also, the calculated effect size showed 36% changes in inhibition, 49% changes in orientation, 50% changes in emotional control, 41% changes in initiation, 48% changes in working memory, 53% changes in planning, 63% changes in the organization of components, and 46% changes of children’s supervision was caused by the difference between the experimental and control groups. Therefore, it can be said that attention-based cognitive rehabilitation has a significant effect on anxiety and executive functions of children with leukemia after chemotherapy.