Objectives: The study aimed to assess 1) the attitudes of medical students in the sixth and seventh years (known as interns in Iran) toward psychiatry as a career choice, and 2) the degree of attractiveness of psychiatry as a career choice, with regard to various defined aspects, before and after an undergraduate psychiatry internship (similar to the medical school psychiatry rotation in the United States, but mandatory in Iran) in three major medical schools in Tehran, the capital of Iran. Method: Sixth- and seventh-year medical students (locally called interns, N=347) at Tehran, Shahid Beheshti, and Iran Universities of Medical Sciences were consecutively invited to complete anonymous self-report questionnaires designed to assess their perceptions of careers in psychiatry before and after internship in psychiatry wards. Also, students evaluated psychiatry in terms of the factors that reflected the degree of attractiveness of this specialty. Results: Positive responses toward choosing psychiatry as a career were seen in 18.8% before and 20.0% after psychiatry rotation. No significant differences were observed in the positive responses before and after psychiatry internship. The students' opinions changed to a more attractive degree in terms of only 3 out of the 13 defined aspects. There was also no significant difference in the total score on attractiveness of psychiatry before and after the psychiatry internship. Conclusions: The study indicated that undergraduate psychiatry internship might not induce more students to consider psychiatry as a possible career. The present pattern of psychiatry education in Iran seems not to positively affect most aspects of medical students' attitudes toward psychiatry. (Contains 3 tables.)