This cross-sectional study aims to find out incidence and severity of stress among undergraduate male and female medical students and explore its association with Body mass index (BMI). A total of 523 young healthy males and females (19- 22 yrs) were categorized as normal, overweight and obese based on their BMI. The level of stress was determined among the participants using PSS-14 questionnaire. Majority of the male participants were found to be overweight with an average BMI 26.95±0.34 while average BMI noted in females was 23.66±1.25. Around 36% of these undergraduate medical students were found to be stressed with average stress score of 26.09± 0.51. In fact among overweight males incidence of stress was 33.66%. However, female subjects showed an increase in percentage prevalence of 94.12% in obese category. Interestingly stress score both in male and females showed a rising trend with maximum in obese being 26.09±0.51 in males and 32.53±1.73 in females. The level of stress was significantly different between obese male and obese females (P<0.00027). Statistically significant correlation (P<0.05) is observed between stress vs. BMI, Stress vs. Weight, Stress vs. Waist Circumference (WC) and stress vs. Hip circumference (HC) in the overweight females. The occurrence and severity of stress is found greater in female undergraduates.