The present study aimed to investigate the causal relationships between economic, social, and cultural capital and academic citizenship behaviors, considering the mediating role of moral character among pre-service teachers at Farhangian University. This research employed a descriptive-correlational method using structural equation modeling (SEM). The statistical population included all pre-service teachers at Farhangian University in Yazd during the 2023–2024 academic year. A total of 360 participants were selected through cluster random sampling, and data from 352 individuals were analyzed. The instruments used included the Cultural Capital Questionnaire (CCQ), Family Social Capital Questionnaire (FSCQ), Family Economic Capital Scale (FECS), Academic Citizenship Behaviors Scale (ACBs), and the Moral Character Questionnaire (MCQ; Khorramayi & Ghaemi, 2018). Data were analyzed using SPSS-26 and SmartPLS-3 software. The findings indicated that social capital had a direct significant effect on academic citizenship behaviors (β = 0.19), while cultural (β = -0.04) and economic capital (β = 0.06) did not. All three types of capital significantly predicted moral character (social: β = 0.13; economic: β = 0.23; cultural: β = 0.20). Moreover, moral character significantly influenced academic citizenship behaviors (β = 0.42). In terms of indirect effects, cultural (β = 0.10) and economic capital (β = 0.08) influenced academic citizenship behaviors through moral character, but the indirect effect of social capital was not significant (β = 0.05). These results highlight the direct role of social capital in enhancing academic citizenship behaviors and underscore the mediating role of moral character in transmitting the effects of cultural and economic capital.