The purpose of the present study was to evaluate outcomes and identify prognostic factors in patients with acute leukemia who were admitted to the intensive care unit (ICU) with septic shock. Medical records of 50 patients with acute leukemia who were treated for septic shock in the Medical ICU of Samsung Medical Centre between September 2001 and June 2006 were retrospectively reviewed. The data were analysed for patient outcomes and for predictors of ICU mortality. ICU mortality and in-hospital mortality were 60% and 68%, respectively. The need for mechanical ventilation (p<0.001), the addition of norepinephrine to dopamine (p<0.001) and a poor Sequential Organ Failure Assessment (SOFA) score (p<0.001) were associated with ICU mortality in the univariate analysis. In the multivariate analysis using the Cox-model, a relapsed/refractory status for leukemia and poor SOFA score were independent predictors for ICU mortality. In conclusion, although the mortality was high in patients with acute leukemia who were admitted to the ICU for septic shock management, it was not high enough to preclude intensive care. Patients with severe organ failure and a relapse/refractory status for leukemia had a significantly worse prognosis.