Large randomized trials have shown that granulocytic colony-stimulating factors (G-CSF and GM-CSF) may be interesting in vivo in promoting neutrophil recovery after high-dose myelosuppressive therapy in some clinical settings. However, any beneficial effect on survival was not yet demonstrated. Granulocytic CSFs act as growth and viability factors on myeloid leukemic cells and their use in acute myeloid leukemias (AML) is theorically not without risk. Paradoxically, these CSFs will maybe be usefull in the future as a part of AML treatment. First, the high early mortality rate in elderly AML patients after intensive chemotherapy should allow a demonstration of a CSF-induced improvement of survival. Secondly, GM-CSF should increase the efficacy of cell cycle dependent cytotoxic drugs based on recruitment of quiescent leukemic cells. Third, granulocytic CSFs should be used to induce programmed cell death in myeloid leukemic cells.