Mucositis occurs in over 90% of patients undergoing stem cell transplantation for hematological malignancies. It is associated with significant morbidity in the form of pain, dysphagia and decreased oral intake, as well as mortality. Palifermin is a recombinant keratinocyte growth factor that has been shown to be effective in decreasing the incidence, severity and duration of mucositis in Phase III trials. Improvement in patient functioning during hematopoietic stem cell transplants has also been reported. This review deals with the preclinical data and the clinical trials that have been carried out with this agent in patients with hematologic malignancies. In addition limited Phase I and II data on solid tumors is available and will be included.