BACKGROUND: The Glasgow Coma Scale is a dependable and objective neurological assessment instrument used for determining and recording a patient's level of consciousness. Therefore, the knowledge, practice, and factors affecting Glasgow coma scale evaluation among nurses working in adult intensive care units of federally administered hospitals in Addis Ababa, Ethiopia, were investigated.METHODS:From April 4 to 24, 2020, 121 Adult Intensive Care Unit nurses at Ethiopian federal hospitals participated in an institutional-based cross-sectional survey with a standardized self-administered questionnaire. The information was entered into Epi-data version 3.1 and then exported to SPSS version 25.0 for analysis. Bivariable and multivariable logistic regressions were used to examine the relationships between independent and dependent variables.RESULT: According to this study, nurses working in the Adult Intensive Care Unit of federal hospitals in Addis Ababa, Ethiopia, had poor knowledge (51.2%) and poor practice (62%) of the Glasgow Coma Scale's basic theoretical notions and competencies. Furthermore, the education and gender of nurses were linked to their level of knowledge and clinical practice. Being a male and having a master's degree were both significantly linked with knowledge(AOR = 4.13, 95% CI: (1.87–9.1)), (AOR=7.4, 95% CI: (1.4-38)) and practice (AOR = 2.7, 95% CI: (1.2–6)), (AOR = 10.4, 95% CI: (2.0–53)) respectively.CONCLUSION: The findings from this study showed that nurses had poor knowledge and application of practice-related clinical scenarios on the Glasgow Coma Scale.KEYWORDS: Glasgow coma scale, knowledge, practice, Intensive Care Unit