The biologic function of the CC chemokine macrophage inflammatory protein-1α (MIP-1α/CCL3) has been extensively studied since its initial identification as a macrophage-derived inflammatory mediator. In addition to its proinflammatory activities, CCL3 negatively regulates the proliferation of hematopoietic stem/progenitor cells (HSPCs). On the basis of this unique function, CCL3 is alternatively referred to as a stem cell inhibitor. This property has prompted many researchers to investigate the effects of CCL3 on normal physiologic hematopoiesis and pathophysiologic processes of hematopoietic malignancies. Consequently, there is accumulating evidence supporting a crucial involvement of CCL3 in the pathophysiology of several types of leukemia arising from neoplastic transformation of HSPCs. In this review we discuss the roles of CCL3 in leukemogenesis and its potential value as a target in a novel therapeutic strategy for the treatment of leukemia.