Objective: The current study was semi-experimentally designed in order to identify the effect of peer education upon breast self-examination (BSE) behaviors and self-esteem among university students.Materials and methods: The study was undertaken with 100 female students who studied at Erzincan University. Peer educators were recruited from the 4th year students. The data were collected with a questionnaire form, BSE skill form and Rosenberg Self-esteem Scale in two phases one month before and after the BSE peer education. For the data assessment; percentage distributions, frequency, mean, standard deviation and Simple T test were employed.Results: The mean age of the participant students was 20.45±1.67 year and all of them were single. It was found that during the first data collection phase, only 16 % of the students performed BSE while during the final data collection phase, the rate of the students performing BSE rose to 77 %. During the first data collection phase, students received a mean score of 2.36±4.13 from BSE skill form while during the last data collection phase they had a mean score of 10.70±3.40 from BSE skill form. When the scores obtained from Rosenberg Self-esteem Scale by the students were examined, it was seen that they received a mean score of 1.20±1.34 during the first data collection phase while they had a mean score of 0.84±1.07 during the final data collection phase.Conclusion: Although short-term feedback was obtained, it was noted that students’ BSE knowledge and skills increased considerably.