Background: Consumption of fast foods has become a hallmark of modern urban and semi -urban life style that have many adverse effects on health. Aim: To assess knowledge and attitudes of students toward fast food in Assiut university. Subject and Method: a descriptive cross sectional research design was used. The study conducted at four faculties of Assiut University among 1217 students who were selected by simple random sample. Tools:In this study utilized three tools for gathering data: the first tool; a structured self-administered questionnaire which included socio-demographic characteristic scale, knowledge and consumption of fast food, the second tool;attitude toward fast food and the last tool; anthropometric measurements. Results: It was found that 63.3% of studied students were males and 52.9% of them with middle socioeconomic class. Also the study cleared that 91.9%from students having fast food, whereas a positive correlation between total score of student's knowledge and attitude toward fast food with statistical significant difference between having fast food, knowledge and attitude. Conclusions: the outcome of present study concluded that lack of students' knowledge and had positive attitude about fast food. Recommendation:Periodic health education programs regarding effects of fast food on health.