the aim of this study was to investigate the relationship between behavioral disorders in children and their mothers' stress through the mediator role of fatigue and coping strategies. The study design was descriptive-correlational which conducted in the 2016-2017 academic year. The participants included 226 elementary students (and their mothers) who were selected by multistage cluster random sampling in Khoramabad. Data were collected by using the Rutter’, s behavioral disorder questionnaire (Rutter, 1967), Coping Strategies Scale (Carver, Scheier & Weintrub, 1989), Fatigue Assessment Scale (De Vries, Michelsen, Van Hack, & Drente, 2004) and Depression‚,Anxiety‚,Stress Scale (Lavibond & Lavibond, 1995). Path analysis was used as statistical method for data analysis. Test of mediation by bootstrapping method established significant mediating role of fatigue and coping strategies in the relationship between behavioral disorders and mothers’,stress. Based on the results, it can be concluded that children's behavioral disorders increase mothers’,stress by increasing their fatigue and ineffective coping strategies, and stress in mothers of children with behavioral disorders who use effective coping strategies is less than that of mothers who use ineffective coping methods. Therefore, planning to educate mothers of children with behavioral disorders in using stress management skills and encouraging them to use effective coping strategies can reduce the stress of these mothers.