: Mental health is the most important factor that influences all aspects of life including academic achievements. The present study aimed at evaluating students’ mental health who started their education in September 2014 at Islamic Azad University of Medical Sciences in Tehran. The present cross-sectional study included 907 medical students (biology, health, medical, paramedical, medical engineering, nursing, and midwifery). All students in the first week of their university activities filled the mental health questionnaire. Subsequently, they were coded and their demographic information was analyzed by SPSS. Our results revealed that 19.5% of the medical students suspected to have a mental disorder.