Background: Breast cancer is the most common among developed and developing countries.rnAccording to the American Cancer Society, about 1.3 million women diagnosed with breastrncancer annually worldwide. The high breast cancer mortality rate in Sub-Saharan Africa has beenrnattributed to a lack of public awareness of the disease which often leads to late diagnosis of therndisease.rnObjective: This study was to assess the knowledge; attitude and practice of breast selfrnexamination of female undergraduate students age 30 years and below of College of Natural andrnComputational Science College of Addis Ababa University Addis Ababa, 2015rnMethods: A cross-sectional study design was conducted from Feb, 2015 to June, 2015 inrnCollege of Natural and Computational Science of Addis Ababa University on randomly selectedrnunder graduate female students. Simple Random Sampling technique was used to recruit 662rnfemale undergraduate students. Data entered using EPI-INFO version 3.5.3 and analysis carriedrnout using SPSS Version 20. Bivariate analysis was used and then entered to multiple logisticrnregressions model and significant variable were identified on the basis of OR, with 95% CI.rnResults: In this study, 597 study subjects involved making a response rate of 90.2%. Aboutrn24.49% of the participants had good knowledge of breast self examination while 29.50% of therninformants had good attitude about BSE. Of the total participants, 25.96% reported that they arernpracticing of breast self examination in the last 12months.rnConclusion: In general, the KAP of the participants were 24.49%, 29.5% and 25.9%rnrespectively. This finding showed that the participants had poor KAP toward BSE. Therefore,rnUniversities and other stake holders should plan to promote provision of information, educationrnand communication targeting young females, and the general community to increase awarenessrnto ward breast self examination