Leukemia is often accompanied by enhanced susceptibility to infection due to compromised B cell and T cell functions. The alterations in macrophage functions in leukemia remain less investigated. Herein, we examined macrophages for their functions and responsiveness to IL-3 and GM-CSF in ENU-induced leukemia in BALB/c mice. We observed that the macrophages from the leukemic mice had less phagocytic activity, reduced chemotactic activity in response to monocyte chemoattractant protein-1(MCP-1), and decreased expression of iNOS, GM-CSF, TLR2, TLR4, IFN-γ and TNF-α. These impaired macrophage functions in leukemic mice were significantly corrected by IL-3 and GM-CSF treatment indicating the therapeutic benefit of these two cytokines in leukemia.