The effect of behavior psychological characteristics and psychological characteristics of accountants on their performance has caught the attention of researchers. The purpose of this study was to design a structural model of relationship between self-efficacy and job performance with mediating role of mental toughness of accountants. The present study is an applied quantitative research which is based on structural equation modeling. In this study, out of 350 employed accountants in the offices of Arvand Free Zone in 2021 selected by simple random sampling, only 200 people were selected as the sample and answered the research questionnaire. The results showed that selfefficacy has a positive effect on job performance. In addition, selfefficacy has a positive effect on mental toughness. The results also show that mental toughness has a positive effect on the job performance of accountants. Moreover, the results also showed that of this study indicate that self-efficacy has a positive effect on the job performance of accountants by mental toughness. Therefore, attention to the positive psychological variables of self-efficacy and mental toughness of accountants of Arvand Free Zone offices can cause positive behavioral