Aim: Leukapheresis is an invasive treatment modality used for hyperleukocytosis. Various drugs and fluids are used during the leukapheresis. Aging itself and associated factors such as increased comorbidity, decreased tolerance to drugs, increased drug toxicity give rise to the application of other treatment modalities in elderly patients. Treatment of acute leukemia in the elderly differs from young patients. Consequently, we assumed that outcome, effectiveness, and side effects of leukapheresis treatment used for acute leukemia patients with hyperleukocytosis may be different in elderly compared to younger patients.