The purpose of this study was to determine the effectiveness of acceptance and commitment based treatment on demographic, social adjustment and mental health of Dissatisfied couples referring to counseling centers in Tehran in 1398. The present study was a quasi-experimental study with pretest-posttest design with experimental and control group. The statistical population was all dissatisfied couples who referred to counseling centers in Tehran who were selected by convenience sampling and were randomly assigned into two experimental (n = 15) and control (n = 15) groups. The experimental group received acceptance and commitment in 8 sessions of 90-minute psychotherapy intervention and the control group remained on the waiting list. Measurement tools used in this study were demographic and social adjustment questionnaire (California, 1953) and mental health questionnaire (Goldberg, 1972). Data analysis was performed by SPSS-v22 software in two parts: descriptive and inferential (covariance). The results showed that group acceptance and commitment psychotherapy improved the "individual-social adjustment" of dissatisfied couples, The results also showed that group acceptance and commitment psychotherapy were effective on "anxiety and insomnia", "social dysfunction" and "depression" of dissatisfied couples, while there was no difference between groups on "physical symptoms". Therefore, it can be said that acceptance and commitment group psychotherapy is an effective way to improve social adjustment and mental health of unhappy couples.