Introduction: Infidelity is one of the most pernicious interpersonal issues in the family, which in many cases could lead to emotional and behavioral symptoms in the person particularly women who have been betrayed. In this regard, the present study was undertaken with the aim to identify the effectiveness of acceptance and commitment group counseling on emotion regulation in women with infidelity trauma.
Methods: The research method was quasi-experimental designed with a pretest-posttest and a control group. The statistical population included all women with the infidelity trauma who were separated from their husbands and referred to counseling clinics and family courts in Tehran in 2017. Thirty couples were selected via the purposive and available sampling method based on the study’s criteria. Then randomly assigned to experimental and control groups, fifteen people in each group, and finally were investigated through dual assessment of pretest-posttest. All participants were asked to complete the Emotion Regulation Questionnaire by Gross & John, 2003. Following the experimental group attended eight sessions of ninety-minute acceptance and commitment group counseling while the control group received non.
Results: The results of the univariate analysis of covariance (ANCOVA) indicated that acceptance and commitment group counseling significantly increased the post-test average scores of emotion regulation in the experimental group. 
Conclusions: Thus, it could be concluded that acceptance and commitment group counseling is an effective way of improving emotion regulation in women with the infidelity trauma and can be used by counselors and therapists in the field of family therapy.