Diet plays a measurable role in breast cancer (BC) prevention. The aims of this study were to assess nutrition-related BC prevention Knowledge, attitudes and practice (KAP) of female university students and to examine the relationship between demographic characteristics of students and their KAP. We conducted a cross-sectional study among 500 female students from Iran University of Medical Science (IUMS). A pretested self-administered questionnaires were used to assess the participants' nutrition-related BC prevention KAP. A total of 500 students completed the survey. Students' knowledge with the mean score of 16.97, significantly varied by age (P= 0.03), the field of study (P= 0.001) and family history of BC (P= 0.01). The mean score of attitudes and practice toward nutrition-related BC prevention factors were 24.86 and 39.39, respectively. A significant relationship was observed between nutrition knowledge and attitude (r = 0.27, P < 0.001). Also, Nutrition-related attitudes were positively correlated with the BC prevention dietary practices (r = 0.23, P < 0.001). Nutrition KAP about BC prevention factors was found to be influenced by individual factors such as age, field of study, familial history of BC, job and residency status. Together, our findings confirm that increasing nutrition knowledge is not sufficient for dietary behavior change, but is necessary.