The present study was conducted to investigate the effectiveness of acceptance and commitment therapy on action cognitive fusion, distress tolerance and forgiveness of divorced women. the research method of the present study was quasi-experimental with pretest, posttest and control group design and a two-month follow-up phase and follow-up period in three months. The statistical population included divorced women who referred to Valiasr and Avai Saadat psychology clinics in Mashhad in the first six months of 2022. 30 divorced women were selected through purposive sampling method and randomly accommodated into experimental and control groups (15 women in the experimental group and 15 in the control group). the experimental group received acceptance and commitment therapy approach (10 sessions) during 10 weeks (90 minutes). the applied questionnaires in this study included cognitive fusion questionnaire (Gillanders et al, 2014), distress tolerance questionnaire (Simons, Gaher, 2005) and forgiveness scale (Rye et al, 2001). the data were analyzed through mixed anova and bonferroni follow-up test via spss23 software. the results showed that acceptance and commitment therapy is effective on the cognitive fusion (f=41.45; eta=0.59; p<0001), distress tolerance (f=27.79; eta=0.50; p<0001) and forgiveness (f=38.02; eta=0.57; p<0001) of the divorced women. Based on the findings of the present research, the acceptance and commitment therapy by forming psychological flexibility and creating psychological acceptance can be used as an effective approach to improve the cognitive fusion, distress tolerance and forgiveness of divorced women.