Mucositis and xerostomia are the most common oral complications of the non-surgical therapy of cancer. Mucositis, a common sequel of radio- (DXR), chemo-(CXR) and radiochemo-therapy in patients with cancer, or patients requiring haemopoietic stem cell transplants (HSCT), has a direct and significant impact on the quality of life and cost of care, and also affects survival – because of the risk of infection. Apart from dose reduction, preventive and treatment options for mucositis are scarce, although multiple agents have been tested. Evidence suggests that cryotherapy, topical benzydamine and amifostine might provide some benefit in specific situations. The recombinant human keratinocyte growth factor Palifermin (Kepivance®) was recently approved as a mucositis intervention in patients receiving conditioning regimens before HSCT for the treatment of haematological malignancies. A number of mechanistically based interventions are in various stages of development. Unfortunately, many other approaches have not been rigorously tested. This paper reviews the clinical features, prevalence, diagnosis, complications, pathogenesis, prophylaxis and management of mucositis.