In recent years, the use of smart communication devices has been widely embraced, leading to psychological disorders such as nomophobia, especially among adolescents. The present study aimed to investigate the effect of personality traits and media literacy on nomophobia, with the mediating role of internet addiction among adolescent students. Studies have shown that the prevalence of this disorder is increasing among adolescents, with many experiencing high levels of nomophobia, and similar moderate to severe levels have also been reported in Spain. Research indicates that personality traits have varying effects on nomophobia. Studies have further demonstrated that higher levels of media literacy and e-health literacy reduce nomophobia in adolescents. Overall, digital literacy enhances adolescents’ ability to use media productively, although heavy smartphone use may sometimes exacerbate it. This study was descriptive-correlational and path analysis. The statistical population included all girls ' and boys ' students of the first secondary level of in non-government schools of the 2nd district of Rasht city in the academic year of 2024-2025, that among them 200 students from four non-governmental girls' and boys' schools, selected as samples by convenience sampling to answer the following questionnaires: Nomophobia Questionnaire (NMP-Q; Yildirim & Correia, 2015), Media Literacy Questionnaire (Falsafi, 2014), Short Form of the NEO Five-Factor Inventory (NEO-FFI; McCrae & Costa, 1992), and Internet Addiction Test (IAT; Young, 1998). Data were analyzed using Pearson correlation coefficient, path analysis and the bootstrap test. The results showed that personality traits and media literacy had a direct and significant effect on nomophobia. The findings also indicated that personality traits except extraversion had a direct and significant effect on internet addiction. In addition, the indirect effect of personality traits on nomophobia through Internet addiction was significant. Therefore, it can be concluded that internet addiction mediated the effect of personality traits on nomophobia; however, the mediating role of internet addiction in the relationship between media literacy and nomophobia was not statistically significant.