The hematopoietic growth factors are glycoproteins that can be produced by recombinant DNA technology. They have many potential clinical uses in acute leukemia; several areas have been explored extensively and much data are available from clinical trials. Other areas are of potential interest, but have a paucity of clinical information. The past decade has seen major strides in the development and clinical application of cytokines in acute leukemia and it is expected that this trend will continue over the next decade as further areas are explored and results of clinical trials mature to enable us to determine the precise role of cytokines in the clinical setting.