Background: Transition from student role to professional role is an important step during the medical course. The discourses of professionalism education are ambiguous in different countries. This study aimed to explain the formation of professionalism in medical students. Methods: The present study was a qualitative study using Jø, rgensen discourse analysis. Participants included 18 medical interns of Iranian universities of medical sciences. The average duration of each interview was 60 to 90 minutes. Data collection tools were in-depth semi-structured interviews and purposive sampling methods. Data collection continued until data saturation. The data analysis method was open coding. Results: The mean age of participants in this study was 25. 65 ±,9. 12. The results included seven concepts,management of professional stress, professional competence, moral competence, human nature of profession, personal development, proper care, and professional identity as well as the nodal point in this discourse analysis was the hidden curriculum. Conclusions: If during the internship, certain professional beliefs and behaviors are not institutionalized in today's students, it can reduce the sensitivity of students' professionalism and makes professional decisions difficult for future physicians. Therefore, the role of formal education in professionalism is important in this regard, considering the role of the hidden curriculum.