en تخصصي Special پژوهشي Research <p><strong>Objective:</strong> The aim of this study was performed to determine the effectiveness of acceptance and commitment therapy on psychological flexibility in obese women in Isfahan, Iran.</p> <p><strong>Materials and Methods:</strong> This was a quasi-experimental pre-test, post-test trial with follow-up. The study population was all of the obese women in Isfahan in 2014 (BMI&ge;30).the sample of study was selected by convenience sampling method. They were randomly assigned to two experimental and control groups (15 per group). The Acceptance and Action Questionnaire for Weight-Related Difficulties (Lillis & Hayes, 2008) was the study instrument. The intervention was 8 sessions of 90 minutes. Acceptance and commitment therapy was provided only to the experimental group. Data was analyzed by SPSS.</p> <p><strong>Results:</strong> Results of covariance analysis showed a significant increase in psychological flexibility at post-test and follow-up stage (<em>P</em><0.05).</p> <p><strong>Conclusion:</strong> Our findings showed that acceptance and commitment therapy has been effective on psychological flexibilityof obese women.</p> Acceptance and Commitment Therapy, Psychological flexibility, Obese women 133 137 http://ijdo.ssu.ac.ir/browse.php?a_code=A-10-30-118&slc_lang=en&sid=1 Leili Nourian Yes MSc, Department of Educational Science and Psychology, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran. Asghar Aghaei No Professor (PHD), Department of Educational Science and Psychology, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran