Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening condition associated with multiple organ dysfunction. We sought to describe ICU management and outcomes in HLH patients meeting HLH-2004 criteria and to identify determinants of mortality. Retrospective study between January 1998 and January 2009. Medical ICU of a teaching hospital. Among the 72 patients fulfilling the HLH-2004 criteria, we report the 56 patients with complete follow-up and no missing data. None. Clinical and laboratory data were abstracted from the medical records. Median SOFA score at admission was 6.5 (IQR, 4–8). At ICU admission, the number of HLH-2004 criteria was 6 (5–7). Sixty-six precipitating factors were found in 52 patients and consisted of 43 tumoral causes (8 Castleman’s diseases, 18 B cell lymphoma and 17 various malignancies), 13 non-viral infections and 10 viral infections. Underlying immune deficiency was present in 38 (67.8%) patients. Etoposide was used in 45 patients, corticosteroids in 31 and intravenous immunoglobulins in 3. Mechanical ventilation was required in 32 patients, vasoactive agents in 30 and renal replacement therapy in 19. Hospital mortality was 29/56 patients. By multivariate analysis, factors associated with increased hospital death were shock at ICU admission [OR, 4.33; 95% confidence interval (95% CI), 1.11–16.90; P = 0.03] and platelet count <30 g/l (OR, 4.75; 95% CI, 1.20–18.81; P = 0.02). B cell lymphoma [odds ratio (OR), 0.17; 95% CI, 0.04–0.80; P = 0.02] and Castleman’s disease (OR, 0.11; 95% CI, 0.02–0.90; P = 0.04) were associated with increased hospital survival. Aggressive supportive care combined with specific treatment of the precipitating factor can produce meaningful survival in patients with HLH responsible for multiple organ failures. Survival is highest in patients with HLH related to Castleman’s disease or B cell lymphoma.