Breast Self-Examination is a method where by women examines their breasts regularly to detect any abnormal swelling or lumps in order to seek prompt medical attention. Knowledge, attitude and practice towards breast self-examination is important among females for screening, early detection and diagnosis of breast Cancer. Objective of the Study was to determine knowledge, attitude and practice regarding breast self-examination among female students in Debre Birhan University, 2013. Institutional based cross sectional study design was used among 374 students. Simple random sampling was used. Data was entered onto Epi Data version 3.01, exported to and analyzed by SPSS version 20 statistical software. From the total of 367 participants 170 (46.3%) had heard about breast self-examination while most 197 (53.7%) had never heard about it. The commonest source of information about breast self-examination was media 118 (69.4%). Majority 273 (74.4%) of the respondents had poor knowledge, most 289 (78.7%) of the respondents had negative attitude and majority 281 (76.6%) of the respondents had poor practice of breast self-examination. Practices have associations with academic year, department and media exposure. Generally, in this study knowledge, attitude and practice of breast self-examination was unsatisfactory. Poor practice is an indication of poor knowledge and negative attitude. Programs should be strengthened about breast self-examination and its importance for early detection of breast cancer.