Background and purpose: Birth of a child with intellectual disability could have a negative impact on mothers, to physical, psychological and social tensions. The purpose of the present research was to determine the effect of stress management training based on cognitive-behavioral approach on improving parent- child relationship and psychological well- being in mothers of children with intellectual disability.

Method: This study is a experimental with pre- test/ post- test and a control group. The population comprised of all mothers of children with intellectual disability of Rasht city in 2016 that 28 participants were selected by available sampling method and assigned to two experimental and control groups (14 mothers in each). To collect the data,‌ Robert mother- child relationship assessment questionnaire (1961) and Ryff‘s scales of psychological well- being (2002) were used. For experimental group, stress management training based on cognitive- behavioral approach was executed at 10 weekly sessions in 45 minutes whereas control group did not have any training.

Results: The results of multivariate analysis of covariance (MANCOVA) showed, this training were improve acceptance and reduce other components of mother- child relationship (overprotection, overindulgence, rejection) and also were improve the psychological well- being of mothers of children with intellectual disability (P< 0/001).

Conclusion: According to the findings of the research, stress management training based on cognitive- behavioral approach is one of the most effective treatments to reduce stress, aggression and improve psychological well- being in mothers of children with intellectual disability.