Despite the many tools available to modern medicine, predicting the neurological and functional status of patients after severe brain injury remains difficult. This analysis evaluates the outcomes of patients with the most severe degree of cerebral function impairment. Retrospective cohort study. Patients hospitalized in the long-term Intensive Care Unit (ICU) department in the Military University Hospital in Prague between 2015-2022. We analyzed patients with severe acquired brain damage from five distinct etiologies whose initial Glasgow Coma Scale (GCS) score was eight or less upon admission to ICU due to neurological damage. Several parameters reflecting the patients' clinical status were evaluated. Overall survival after discharge from the ICU was calculated according to the Kaplan-Meier model with comparison between traumatic (TR) and non-traumatic (non-TR) etiologies. The analyzed cohort of 221 patients consisted of 116 patients of TR and 105 of non-TR etiology. There was no significant difference in overall survival between TR and non-TR groups. The length of hospitalization in the ICU was similar in both groups with a median of 94 days. The majority of patients had an improvement of GCS during the hospitalization with a median improvement of five points. GCS improvement occurred in the vast majority of patients regardless of TR or non-TR etiology. We did not observe a statistically significant difference in mortality or log-term neurological status between patients with severe brain injury of traumatic or non-traumatic etiology for the duration of our follow-up. The majority of patients had improved GCS, were successfully decannulated, but remained disabled with severe limitations of functional independence. The return of the patient to normal life is a rehabilitation challenge, regardless of the etiology of brain injury, and is extremely influenced by the level of development of neurorehabilitation programs in individual institutions, the severity of brain injury, and the individual motivation of the patient.