Background and purpose: Managers’ competencies leave a decisive effect on the mental health of staff. The present research intends to investigate the influence of emotional-social competencies on the mental health of the staff. Method: the current research is practical in its purpose and correlative regarding data gathering. The statistical community included all the staff of Pegah Company in District 3, which were 221 persons selected through simple random sampling. The assessment tools of this study were standard Boyatzis questionnaire for emotional-social competencies of managers from the staff’s point of view and Goldberg general health questionnaire for the mental health of the staff. The validity (content, convergent, divergent) and reliability (load factor, composite reliability, and Cronbach’s alpha coefficient) were employed which indicated that assessment tools have acceptable validity and reliability; and the gathered data were analyzed by SMART-PLS2 and descriptive statistics with SPSS21. Findings: the outcomes of this study indicate that t coefficient ranges between emotional-social competency, emotional competency and social competency with the mental health which were respectively 7.46, 5.21, and 10.46. Also, the values of R2 coefficient of determination were 0.71, 0.67, and 0.54 respectively which are desired results. It shows that emotional-social competency, emotional competency and social competency leave positive and significant impacts on mental health. Conclusion: the results of this study attests to the importance of managers’ emotional-social competency for mental health of staff. Thus, the organizations should employ some strategies for the managers to acquire emotional-social competencies and accordingly improve mental health of staff and attain organizational goals.