This cross sectional study was carried out to assess the nutritional status of medical students and to determine its relation to their life style. The study involved 317 students at, Am Shams University. Anthropometric measurements such as weight, height, mid-arm circumference, triceps skin fold thickness and body mass index were measured. The students completed a self-administered questionnaire including data about some life style factors and food-frequency consumption. The study revealed that 41.3% of the students were of normal weight while 9.5% of the sample were underweight, 36.9% were overweight and 12.5% were obese. The mean mid upper arm circumference (MUAC) and mid arm muscle circumference (MAMC) of males was significant higher than that of females, while the mean triceps skin fold (TSF) of females was significant higher than that of males. The food frequency questionnaire analysis showed that most of students consume all food groups items faire. There was no statistical significant difference between the body mass index (BMI) of students and different types of food consumption. About two thirds of the students used to practice exercise, 26.9% of the students practiced exercise for less than 2 hours per week, while 33.9% of them for more than 2 hours. There was no statistical significant difference between the BMI of students and different types of exercise. However, there was significant higher percentage of males play sports and practice running (44.7% and 19.4% respectively) compared to (11.7% and 8.1%) of females. Sixty four percent of the students usually have regular meals. About 87.2% of obese compared to 64.9% of normal weight students eat snacks between meals, the difference was statistically significant. Obese individuals eat more during watching television and during feeling of stress compared to non-obese and the difference was statistically significant. The duration of practicing exercise, sports and playing computer was significantly higher in males than females. However, the duration of watching television was significantly higher in females than males. Logistic regression analysis results showed that family history of obesity and some life style factors as duration of computer use, eating more during stress time and snacking between meals were important risk factors for obesity. We concluded that about half of medical students were overweight and obese. The most important life style factors responsible for obesity were longer time spent using computer, eating more during time of stress and snacking between meals. Also, genetic factors played an important role in development of obesity. It is recommended to develop nutritional education and physical activities programs to face the problem of increasing the rate of overweight and obesity among university students.