Background & Objectives: Various studies have shown that women who are overweight and obese, have lower mental health and higher anxiety disorders than normal people. Anxiety disorders that are associated with obese and overweight women are social anxiety disorders. One of the effective treatments in this area is acceptance and commitment therapy. The main purpose of this treatment is to provide psychological flexibility. Women in the community are at risk of developing mental illness, especially in relation to anxiety disorders in association with obesity, successful treatment of these disorders can play an important role in promoting mental health. Therefore, the purpose of this study was to investigate the effectiveness of acceptance and commitment therapy on social anxiety and its subscales are fear, avoidance, physiological discomfort and BMI in overweight women. Methods: This study is an applied and quasi– experimental research with the experimental and control group. The statistical population of the study consisted of all overweight women with BMI greater than 30 in district 1 of Tehran in the years 2018– 2019 who referred to psychotherapy centers for psychological treatment. The sample consisted of 40 individuals who were selected by convenience sampling and were randomly divided into experimental and control groups. Intervention was performed as acceptance and commitment therapy sessions in the experimental group. For measure social anxiety use the Social Anxiety Inventory (Connor et al, 2000) and body mass index (BMI), which was calculated by dividing the weight (in kg) by the square of the height (in meters). acceptance and commitment therapy sessions were grouped in 8 sessions of 60 minutes and one session per week. For descriptive statistics analysis the mean and standard deviation were used. For Inferential statistics analysis was used to show the natural distribution of data using Shapiro– Wilk test and also to investigate the effect of 8 sessions of acceptance and commitment based intervention on the variables studied using ANCOVA. SPSS software version 25 with significance level 0. 05 was performed. Results: In general, the findings indicated a significant effect of a course of acceptance and commitment based treatment on social anxiety (p<0. 001), fear (p<0. 001), avoidance (p<0. 001), Physiological discomfort (p<0. 001) and body mass index (p<0. 001) were overweight in women. Also, the effect size was in social anxiety (0. 89), in fear (0. 75), avoidance (0. 77), physiological discomfort (0. 59) subscales, and in body mass index (0. 70), which indicates the strong effect of group– based and acceptance– based group therapy. Conclusion: Based on the findings of this study acceptance and commitment therapy, with the help of increased psychological flexibility, reduces empirical avoidance and treats overweight and adolescents by accepting individual thoughts and feelings and social anxiety. And it causes weight loss in these people.