Abstract Background: A head injury is a critical illness that requires specific treatments in the intermediate care room at the hospital. A head-injured patient may experience changes in his condition, namely decreased consciousness. Decreased consciousness will affect the prognosis and mortality of patients, in case in critical care areas, the appropriate measurement scale is needed, such as Glascow Koma Scale (GCS) and Full Outline of Un Responding (FOUR) to assess the level of consciousness. Objective: Identify the level of consciousness measurement using GCS and FOUR to assess mortality in head-injured patients in critical care areas. Methods: The study was conducted by reviewing eleven journals from Portal Garuda, EBSCO, PROQUEST, CANGAGE and DOAJ published from 2010 to 2020 Results: GCS and FOUR can be used in predicting mortality of head-injured patients in critical care wards. Conclusion: GCS and FOUR are effective measuring instruments to assess mortality in head-injured patients, however it is more appropriate to use FOUR for patients with intubation. Keywords: GCS, FOUR, Mortality, Brain Injury.