Objective: The birth of a child with special needs causes problems for the family. The aim of this study was to determine the effectiveness of acceptance and commitment based therapy on the psychological capital of mothers of children with autism spectrum disorder. Methods: The research was quasi-experimental with pretest and posttest. The statistical population included all mothers of boys aged 8 to 12 years with autism spectrum disorder in medical and rehabilitation centers in Yazd in 1398. Thirty mothers were selected by available sampling method from Survival Rehabilitation Center as a research sample and randomly placed in two experimental (n = 15) and control (n = 15) groups. Subjects were assessed by the Psychological Capital Questionnaire. Intervention program of acceptance and commitment-based treatment was performed in 10 sessions of 90 minutes only on the experimental group and the control group did not receive any intervention. Data were analyzed using multivariate analysis of covariance through SPSS24 software. Results: The results showed that acceptance and commitment-based therapy improved the psychological capital of mothers of children with autism spectrum disorder (p 0.01). It can be concluded that acceptance and commitment-based therapy helps mothers of children with autism spectrum disorder to consciously accept their suffering and understand that it is part of the life process and to make more conscious choices in situations of suffering and be more effective. Conclusion: Therefore, according to this finding, therapists can use acceptance and commitment-based therapy as an intervention method in this area.
