Traumatic Brain Injury is the most important severe injury on the nerve system, lining of the brain, cranial nerve including fracture on the skull, damage on soft tissue in the head and face that are both primary and secondary damage. Traumatic brain injury had become health, social, economic matter that caused death and permanent dissability in mature age. Experts mentioned that the rate of road accident in Indonesia was still quite high, that was 90%. The objective of the research was finding out the illustration of the knowledge level of ER nurses on handling patient with traumatic brain injury at PKU Muhammadiyah Hospital Yogyakarta and PKU Muhammadiyah Gamping Hospital. The Methode of the research was descriptive quantitative with Cross Sectional. The sample collecting was Total Sampling. The total number of respondents were 38 ER nurses. The research was from April until June 2016. The validity test used was Content Validity Index (CVI) and Pearson Product Moment that was r count ≥ r table (0,3202) and the reliability test used Kuder-Richardson (KR 20) that was r ≥ 0,6. The data analysis used descriptive with the result of frequency and percentage. The Result : indicated that the majority of the respondents who were in the early maturity (20-40 years old) or (74%), male (53%), with D III degree (71%), had 6-10 and more than 10 years experience as ER nurse (34%), information on traumatic brain injury handling was majority from printed or electronic media (60%), mostly had PPGD training experience (95%) and the number of the training year was majority in 2012 (60%). The result of the research indicated that there were 13respondents (34%) in high category knowledge level and 17 respondents (45%) were in medium category knowledge level. The Conclusion was that the illustration of the knowledge level of ER nurses on handling patient with traumatic brain injury at PKU Muhammadiyah Hospital Yogyakarta and PKU Muhammadiyah Gamping Hospital was categorized as medium