The Glasgow Coma Scale (GCS) is used as a tool to assess the level of consciousness in a brain injury patient. In this study, special attention was given to investigate the accuracy of Glasgow Coma Scale (GCS) knowledge and performance among Vietnamese nurses. On the basis of a nurse sample in CR hospital, a cross-sectional descriptive study was performed. The designed questionnaire was used to identify the accuracy of the nurses’ knowledge of the GCS and the accuracy of the nurses’ GCS score of each patient. By taking into account the relationship of the variables, a series of analyses were conducted by t test, chi-square test, and ANOVA. The results indicated that most of the nurses (>90%) answered correctly with respect to GCS basic knowledge; however, 52.1% of the nurses made errors in the clinical scenario section. In the performance section, high accuracy was shown on the motor and verbal subscale (77.9% and 74.5%). Moderate accuracy was shown for eye score (67.4%). All three components revealed a low accuracy percentage (42.1%). Consequently, it was found that nurses made significant errors in their performance of the GCS even though they showed a high level of theoretical knowledge. Moreover, the significant difference in knowledge between the performance groups was subsequently explored to emphasize the importance of GCS education
