This study investigated the determinants of political participation among young Tehran residents and identified the factors that may strengthen their motivation to participate in the 2028 presidential election. The research employed an exploratory–explanatory mixed-methods design. In the qualitative phase, data were collected through 20 in-depth semi-structured interviews with young people and experts using purposive and snowball sampling, and were analyzed through thematic analysis following Braun and Clarke’s approach. The quality of the qualitative findings was assessed using Guba and Lincoln’s trustworthiness criteria, while intercoder reliability was examined through Holsti’s formula. In the quantitative phase, the statistical population consisted of young people aged 19 to 25 across Tehran’s 22 municipal districts, from whom 451 participants were selected using multistage cluster sampling. The research instrument was a researcher-developed questionnaire whose validity was confirmed through content validity ratio (CVR), content validity index (CVI), and confirmatory factor analysis, including average variance extracted (AVE) and the Fornell–Larcker criterion. Reliability was established using Cronbach’s alpha and composite reliability (CR). Quantitative data were analyzed using SPSS and structural equation modeling.The findings indicated that the mean level of inclination toward political participation was below the average level (M=2.85). Among the inhibiting factors, corruption and rent-seeking (M=4.45), distrust in political promises (M=4.32), and livelihood problems (M=4.25) had the strongest deterrent effects, whereas foreign media propaganda (M=2.55) showed the weakest influence. The structural model further revealed that institutional trust (β=0.62) and political efficacy (β=0.51)had significant positive effects on political participation, while media consumption (β=−0.28) exerted a significant negative effect. In the qualitative phase, three overarching themes were identified: identity–rational drivers, structural–attitudinal barriers, and communicative–media-related factors. Overall, the decline in youth political participation reflects structural dissatisfaction, erosion of institutional trust, and a growing sense of politically learned helplessness.