Haematopoietic colony stimulating factors (CSFs) stimulate the proliferation, differentiation and functional activity of myelocytes. Since approval of the use of these factors in patients with chemotherapy-induced neutropenia, patients undergoing autologous bone marrow transplantation (BMT) and patients with delayed engraftment after BMT, several other potential clinical uses have been described. Current and potential future clinical applications of CSFs will be reviewed.