Stress is a major problem eventually faced by the students during their studies period. There is an imbalance between environmental conditions and ability of individuals to adapt. When it is concerned with medical students, it has been recognized as the major factor responsible for the negative effect on physical and psychological health. To evaluate stress and perception of physical problem with obesity in medical students. The present descriptive cross-sectional study was conducted in Kathmandu Medical College Teaching Hospital, Duwakot from May 2015 to July 2015. This study encompassed 435 medical students- including both sexes aged 17-27 years. A predesigned and structured questionnaire was used as data collection tool and height and weight were measured and Body Mass Index (BMI) was calculated. In this present study 38.4% (167) were female and 61.6% (268) were male participants. The level of stress was significantly higher in female students when it was compared with male students and various stress associated precipitation factor were also present which was statistically significant as p=<0.05. In this study there was no significant association found between level of stress and perception of physical problem with obesity. Incidence of stress was significantly higher in medical students contributing a leading role in physical and psychological problems. Due to stress students are under the negative effect to perform various activities. The effect of stress and its associated precipitating factor influencing medical student needs to be minimized. The students must practice proper eating behaviors and encourage physical activity to prevent obesity. So, an essential step has to be taken as a first line of detection and defense for better health and wellbeing.