Objective: Taking the appropriate psychological actions to boost the mental health of patients with breast cancer is critical. This research was performed with the aim of examining the effectiveness of cognitive-behavioral group therapy on reducing body image concerns in patients with breast cancer.

Methodology: TThe method used was quasi-experimental with a pretest-posttest plan and control group. Therefore, 40 patients with breast cancer who had referred to the oncology and radiotherapy department of Imam Hossein Hospital of Tehran were selected by convenience sampling method and organized into two groups: experimental and control group. Both groups were pretested by using demographic and body image concern questionnaires. Then the experimental group received cognitive-behavioral group therapy training for eight sessions and the control group did not receive any intervention. Afterwards, both groups were post-tested, and the data were analyzed by using SPSS software with descriptive and inferential statistics methods.

Findings: The findings showed that the cognitive-behavioral group therapy training significantly contributed to the reduction of body image concern in patients with cancer (p < 0.001).

Conclusions: It was concluded from this research that cognitive-behavioral group therapy training is an effective strategy to help patients with breast cancer who suffer from the concern about body image due to its high efficiency, especially when it was held in groups, it had low cost, and it was acceptable by the patients.