Exercise and physical activity have well known physical and mental benefits, especially during students' life .This study was conducted to evaluate physical activity among students of Tehran University of Medical Sciences (TUMS). We have randomly recruited students of TUMS in the 2017-2018 academic year to report their routine physical activity through filling out the Persian version of the Global Physical Activity Questionnaire as well as demographic characteristics among 12 different schools. Accordingly, we classified the physical activity of participants into three groups (high, moderate, and low). From a total of 425 students, data from 417 were analyzed. The age range of students was from 18 to 48, with a mean (SD) of 25.8 (5.43) years. 53.5% and 46.5% of participants were male and female, respectively. Students were classified into 3 categories of high (41%), medium (38%), and low (21%) physical activity. In the present study, 87.3% and 12.7% of students were active and inactive, respectively. There was a significant difference in the overall activity level between genders and work-related activity between students of clinical and non-clinical settings. No significant differences were found between physical activity level and other demographic data. Our results showed that the majority of students had a physical activity of more than 600 MET-min/week. No significant relationship was found between physical activity and age, school, GPA, and BMI. Compared to the national activity report, students of TUMS were at the proper level of physical activity. However, further research is needed to confirm these results.