Background employing universal precautions means taking precautions with everybody. If precautions are taken with everyone, health care workers do not have to make assumptions about people's lifestyles and risk of infection. Objectives: The main objective of the study was, to assess the knowledge, attitude and practices about universal precautions among emergency medical professionals and factors associated with its practice in emergency unit. Methods: This hospital based cross sectional descriptive survey was conducted in Tikur Anbessa Specialized hospital, AAU from February through June 2013. The study was carried out using a structured questionnaire which was self-administered to all emergency medicine personnel after preliminary introduction at a plenary session. The study was use both quantitative (which was self-administered) & qualitative(to which an Observation check-list was used to observe whether or not the staff members involved in patient management is using an appropriate technique and timing as per the set guideline) methods. Data was entered, cleaned and analyzed using SPSS for Windows version 16. Frequencies, percentage and graphs was used for descriptive purposes. Study period –study period was from February 2013 to June 2013.The total budget for the accomplishing of this study was 18,465.50 ETB. Results-Only 15(24.6%) of the respondents know the presence of anti HIV prophylaxis after sustaining needle stick or sharp injuries while 46 (75.4%) didn’t know. The respondents who had perceived risk of acquiring HIV infection from their health facility waste, when disposed improperly, 2 said the risk would be for HCW, 3 for supportive staff, 40 (65.6%) for both health professionals & supportive staff and 8 said would be for Health Professionals, Supportive staff, the client / patient & the community. Among the emergency medicine professionals 36(59%) perceived that oxygen delivery materials like mask, nasal cannula & prong can be reusable whereas 25(41%) perceived as this materials can’t be reused. Concerning needle recapping after use, 51(83.6%) the respondents perceived that it should not be recapped and the remaining 10(16.4%) were said should be recapped after use. Discussion-Poor hand washing practice by emergency medicine professionals were found before and after touching the patients were found. Emergency medicine professionals were not properly handling, and disposing used Needle/sharp materials in the study area. Personal protective devices particularly mask and eye goggles, boots etc. were not available during the survey.