AIM: To assess reliability by comparing the Full Outline of Unresponsiveness (FOUR) scores and Glasgow Coma Scale (GCS) values assigned by specialists from two different fields to patients in the Anesthesiology and Reanimation and Neurosurgery intensive care units. MATERIAL and METHODS: This study was conducted between March 2017 and June 2017 at Selcuk University Faculty of Medicine, Departments of Anesthesiology and Reanimation and Neurosurgery. Seventy-nine patients aged 18-65 years who were treated for at least 24 hours in the intensive care unit were independently assessed by two raters, an anesthesiologist and a neurosurgeon,using FOUR and GCS. The Kolmogorov-Smirnov normality test was applied for continuous variables, and SPSS 20.0 version software was used for data analyses. RESULTS: There were no significant differences between FOUR scores and GCS values given by the two raters. The mortality rate among patients with low scores on both FOUR and GCS was higher than the hospital mortality rate. CONCLUSION: Considering that FOUR score allows a more detailed neurological evaluation than GCS, and our findings suggest that FOUR score is more useful for patients who are unconscious or dependent on mechanical ventilation.