This study investigated the effectiveness of cognitive-behavioral therapy (CBT) on math anxiety and math self-concept in elementary school students using an experimental design. For this study, we selected 30 students with high mathematics anxiety and low mathematics self-concept from a larger sample of 142 elementary school students in Arak City, Iran. We randomly assigned participants to either the control or treatment group. The treatment group took part in a 12-session program based on a cognitive-behavioral approach. Math Anxiety Rating Scale (MARS) and PALMA math self-concept were used to measure math anxiety and mathematics self-concept. The finding shows that participants in the treatment group reported statistically lower mathematics anxiety and higher mathematics self-concept after participating in group sessions based on CBT intervention.