Background: Systemic vasculitis may cause life threatening complications requiring admission to an intensive care unit (ICU). The aim of this study was to evaluate outcomes of systemic vasculitis patients admitted to the ICU and to identify prognosis factors.Methods: During a ten-year period, records of 31 adult patients with systemic vasculitis admitted to ICUs (median age: 63 y.o, sex ratio M/F: 21/10, SAPS II: 40) were reviewed including clinical and biological parameters, use of mechanical ventilation, catecholamine or/and dialysis support. Mortality was assessed and data were analyzed to identify predictive factors of outcome.Results: Causes of ICU admissions were active manifestation of vasculitis (n = 19), septic shock (n = 8) and miscellaneous (n = 4). Sixteen patients (52%) died in ICU. By univariate analysis, mortality was associated with higher SOFA (p = 0.006) and SAPS II (p = 0.004) scores. The need for a catecholamine support or/and a renal replacement therapy, and the occurrence of an ARDS significantly worsen the prognosis. By multivariate analysis, only SAPS II (Odd ratio: 1.16, 95% CI [1.01; 1.33]) and BVAS scores (Odd ratio: 1.16, 95% CI = [1.01; 1.34]) were predictive of mortality.Conclusion: The mortality rate of severe vasculitis requiring an admission to ICU was high. High levels of SAPS II and BVAS scores at admission were predictive of mortality.