Background: Breast cancer is the leading cause of cancer related deaths over world. Screening and early detection of disease is the cornerstone for disease prevention. Breast Self-Examination is a screening technique that involves examining ones breasts for lumps distortions or swelling. The practice when regularly done enables one to get familiar with their normal breast structure which in turn helps women to detect abnormal lumps in order to seek prompt medical assistance. Objective: To assess attitudes, practices associated factor of BSE among female health worker at Gambella public health facility Gambella Town, South West Ethiopia. Methods: Institution based cross sectional study was conducted from JANUARY to JUNE, 2019. One hundred sixteen seven health professional was recruited for the study by using total population sampling technique. A structured self-administered questionnaire was used for data collection. In addition to descriptive statistics and logistic regression analysis was applied to assess the association between dependent and independent variables of the study. Result: A total of 161 female health worker participated in the study yielding 95.83% response rate. Out of all, 61.5% of them had BSE practice, and only 42.9% had good BSE practice. Compared to female health workers who the last time performed breast self-examination one week ago, those who performed 3-6 months ago and less than a year ago had lower odds of good BSE practice, (AOR = 0.01, 95% CI: 0.00-0.07) and (AOR = 0.10, 95% CI: 0.01-0.96) respectively. Conclusion: The proportion of female health workers practicing BSE is low, so concerned bodies especially the health bureau should routinely offer training for female health workers to increase their knowledge about Breast cancer correct technique of BSE.