Mucositis occurs in < or = 98% of patients undergoing stem cell transplant for haematological malignancies and is associated with significant morbidity and mortality. Patients with severe mucositis have more pain, more difficulty with daily activities such as talking and eating, and are more likely to have bacteraemia. Palifermin is a keratinocyte growth factor that has been shown to decrease severity and duration of mucositis with a concurrent decrease in patient-reported symptoms and use of narcotics and total parenteral nutrition. Research is ongoing into palifermin's potential ability to decrease graft-versus-host disease and improve reconstitution of functional T lymphocytes after allogeneic stem cell transplant, to hasten wound healing and to reduce mucositis following external beam radiation therapy in solid tumour patients.