The prognosis of oncology patients admitted to the intensive care unit (ICU) is considered poor. Our objective was to analyze the characteristics and predictive factors of death in the ICU and functional outcome following ICU treatment for neuro-oncology patients. A retrospective study was conducted on all patients with primary brain tumor admitted to our institutional ICU for medical indications. Predictive impact on the risk of death in the ICU was analyzed as well as the functional status was evaluated prior and following ICU discharge. Seventy-one patients were admitted to the ICU. ICU admission indications were refractory seizures (41%) and septic shock (17%). On admission, 16% had multi-organ failure. Ventilation was necessary for 41% and catecholamines for 13%. Twenty-two percent of patients died in the ICU. By multivariate analysis, predictive factors associated with an increased risk of ICU death were: non-neurological cause of admission [p=0.045; odds ratio (OR) 5.405], multiple organ failure (p=0.021; OR 8.027), respiratory failure (p=0.006; OR 9.615), and hemodynamic failure (p=0.008; OR 10.111). In contrast, tumor type (p=0.678) and disease control status (p=0.380) were not associated with an increased risk of ICU death. Among the 35 evaluable patients, 77% presented with a stable or improved Karnofsky performance status following ICU hospitalization compared with the ongoing status before discharge. In patients with primary brain tumor admitted to the ICU, predictive factors of death appear to be similar to those described in non-oncology patients. ICU hospitalization is generally not associated with a subsequent decrease in the functional status.