en روانشناسی Psychology پژوهشي Research <div style="text-align: justify;"><strong>Background and Objective</strong>: Breast cancer is one of the leading causes of death in women worldwide. Traditional treatment methods for breast cancer often disrupt the quality of life (QOL) of patients. Therefore, oncology care has shifted towards improving the QOL of cancer patients. This study aims to investigate the effectiveness of cognitive-behavioral stress management (CBSM) therapy on the QOL of women with breast cancer in Iran.<br> <strong>Materials & Methods</strong>: This is a quasi-experimental study with a pre-test, post-test, and follow-up design. Participants were 30 women aged 30-50 years with breast cancer (stage 1-2) referred to Imam Khomeini Hospital and Baghban Clinic in Sari, Iran. They were selected using a convenience sampling method and were randomly assigned to intervention and control group. Both groups completed the short form of the World Health Organization QOL scale (WHOQOL-BREF). The intervention group participated in ten 120-minute sessions of group CBSM. Immediately after and one month after the intervention, both groups were re-evaluated and the data were analyzed using the repeated measures ANOVA in SPSS software, version 22.<br> <strong>Results</strong>: The CBSM significantly improved the QOL of women (P<0.05). This effect maintained for one month.<br> <strong>Conclusion</strong>: The CBSM therapy can effectively improve the QOL of Iranian women with breast cancer, which can enable them to cope better with the treatment process.&nbsp;<br> &nbsp;</div> <span style="font-size:12pt"><span style="text-justify:kashida"><span style="text-kashida:0%"><span style="line-height:150%"><span new="" roman="" style="font-family:" times=""><span dir="RTL" lang="AR-SA" style="font-size:10.0pt"><span style="line-height:150%"><span style="font-family:"TimesNewRomanPSMT","serif""></span></span></span></span></span></span></span></span> Cognitive behavioral therapy, Stress management, Breast cancer, Quality of life (QOL) ​​​​​​​ 113 122 http://cpr.mazums.ac.ir/browse.php?a_code=A-10-192-1&slc_lang=en&sid=1 Fatemeh Toghani fatemetoghani@yahoo.com 10031947532846001993 10031947532846001993 No Department of Clinical Psychology, Faculty of Medicine, Sari Branch, Islamic Azad University, Sari, Iran. Bahram Mirzaian bahrammirzaian@gmail.com 10031947532846001994 10031947532846001994 Yes Department of Clinical Psychology, Faculty of Medicine, Sari Branch, Islamic Azad University, Sari, Iran. Ehsan Zaboli paya_1358@yahoo.com 10031947532846001995 10031947532846001995 No Department of Clinical Psychology, Faculty of Medicine, Sari Branch, Islamic Azad University, Sari, Iran. Farzaneh Amini aminifarzaneh40@gmail.com 10031947532846001996 10031947532846001996 No Department of Clinical Psychology, Faculty of Medicine, Sari Branch, Islamic Azad University, Sari, Iran.