Backgrounds: The present study is an applied and descriptive-analytical in terms of purpose and method, respectively. The aim of this study is studying the ACT training on reducing obsession in women with M.S. This clinical trial study was conducted with pre-test, post-test and follow-up with experimental and control groups.

Method: In this study, subjects were selected by convenience sampling. In this study, SPSS software was used to analyze the questionnaire data and the covariance test was used to test the research hypotheses. The results showed that the value of the relevant multivariate statistics, i.e. Wilkes lambda, was significant (2η = 0.850, p = 0.000, F = 0.026). Therefore, it can be concluded that there is a significant difference between the two groups in terms of scores of obsessive beliefs.

Result: Therefore, we conclude that multivariate analysis of covariance is generally significant. the results of the analysis show that the method of acceptance and commitment therapy has been effective in the rate of obsessive beliefs in obsessive patients with MS.

Conclusion: by implementing this approach in schools by school counselors, counseling clinics and welfare centers, many other mental illnesses can be prevented so that the next generation does not get involved in mental problems and, consequently, physical problems. Therefore, due to the effectiveness of the acceptance and commitment therapy in reducing obsessive-compulsive disorder, this treatment can be used for chronic diseases such as schizophrenia, diabetes, chronic pain, etc.