Background. Standard precautions are infection control techniques against pathogenic microorganisms that are present in human blood and can cause disease in humans. Objective. This study aims to assess knowledge and practice of standard precautions against blood borne pathogens among doctors and nurses in adult emergency room, Addis Ababa, Ethiopia. Methods. Institutional based cross sectional study was conducted from February to March 2018. A total of 128 study participants selected from four public hospitals were enrolled in this study. Data were collected using standardized pretested questionnaire and thencoded, entered, checked for completeness, and analyzed using SPSS version-23 statisticalsoftware. Chi-square test was used to measure the association between variables. P values