Background: Obesity has become an important public health problem in adolescents due to rapid increase of prevalence rate associated with sever co-morbidities.Aim: The aim of this study was to assess the prevalence and predisposing factors of obesity among mansoura university students. Methods: Descriptive cross sectional design was used to carry out this study at eighteen faculities at mansoura university. The sample size was 589 students. Five tools were used for data collection including socioeconomic scale, structured interviewing questionnaires to assess students health status and dietary habits, self administerd structured questionnaire to assess students knowledge and ATOP scale to assess students attitude toward overweight and obesity. Results:The study showed that 56.4% of university students were overweight and obese. Fifty eight percent of students showed unsatisfactory score level of dietary habits. Most of them had poor knowledge score level and 30.9% of them had negative attitude toward overweight and obesity.Conclusion:The study concluded that the prevalence of overweight and obesity among students at mansoura university was high and there are many factors affecting this high prevalence including dietary habits, knowledge and attitude.Recommendations:The study recommended that health educational programs should be directed to university students on the predisposing factors of obesity and health eating habits.