Cancer is one of the leading causes of death worldwide. This issue has led doctors and psychologists to seek to discover the causes, treatment and ultimately improve the mental health of this group of patients. The present study was conducted with the aim of investigating the training based on group schema therapy on emotional disturbance and body disfigurement in patients with breast cancer. The present study was quasi-experimental and of pre-test-post-test design with a control group. The statistical population of this research included all patients referred to medical centers and hospitals in Shiraz from July 2023 to September 2023 diagnosed with breast cancer. Using the targeted sampling method, 50 women with breast cancer were selected and randomly assigned to 2 groups (control and experimental). The experimental group received group schema therapy educational intervention in 8 sessions of 45 minutes and 1 session per week. The control group did not receive any intervention; The questionnaires used in this research included the Depression, Anxiety and Stress Questionnaire (DASS-21) by Lovibond and Lovibond (1995) and Dysmorphic concern Questionnaire by Oosthuizen et al (1998). SPSS version 24 software and covariance analysis were used for data analysis. The results showed that group schema therapy educational protocols had a significant effect on reducing emotional disturbance and body ugliness in women with breast cancer (p≤0.001). The effect size for emotional disturbance and body deformity was 0.576 and 0.247, respectively. Training based on group schema therapy was confirmed in the present study to reduce emotional disturbance and body deformity. It is suggested to use this type of treatment to help women with breast cancer.