Although the issue of moral identity and morality is under investigation for the last many years, there is still a need to investigate its role in how it promotes behavior. This study tends to extend this string of literature and attempted to investigate the mediating role of moral reasoning among the elements of moral culture, prosocial behavior, and psychological wellbeing. For this purpose, college students were selected as participants in this study. For this purpose, a two-wave strategy was followed to collect data. In the first wave of questionnaire distribution, 600 college students were contacted to complete the response. A hidden secret code was allotted to each questionnaire to trace the respondent for the second wave. From the distributed 600 questionnaires, 507 questionnaires were received back. At this stage, demographic characteristics and questions related to both the independent variables were asked from the respondents. While in the next wave, 448 questionnaires were received back from the redistributed questionnaires in the second wave. After discarding the incomplete and partially filled questionnaires (17 questionnaires) there were left 431 useable responses. These responses were used to run the tests through structural equation modeling (SEM) through assessment of measurement and structural model. Results indicate that symbolization promotes positive changes in the psychological wellbeing of the students and prosocial behavior of the college students. Moreover, internalization can promote psychological wellbeing. However, the impact of internalization on the prosocial behavior of college students has not been found statistically significant. Moreover, it can be safely concluded that moral reasoning has the potency to mediate the relationship of symbolization and psychological wellbeing as well as prosocial behavior. Moral reasoning also mediates the relationship between internalization and psychological well-being and prosocial behavior.