The purpose of this research was to investigate the effect of social capital on young people's mental health, considering the mediating role of national identity. The method of this research was a survey. 377 youths aged 18 to 29 from Yasouj city were determined and selected using a multi-stage cluster sampling method. Based on the structural equations results, there was a positive and significant relationship between social capital and the national identity of youth (P < 0.01). Also, there was a positive and meaningful relationship between national identity and the mental health of young people (P < 0.05). Still, there was no significant relationship between social capital and the mental health of young people (P > 0.05). The coefficients of determination showed that 39% of the variance of national identity was explained by social capital and 61% of the variance of youth mental health was explained by social capital and national identity. Finally, the results showed that social capital alone does not have a significant effect on the mental health of young people, but the variable of national identity could have a significant effect on the mental health of young people.
