With the fall in mortality from infectious diseases, the· impact of childhood cancer in the Western World has increased to become the second commonest cause of death in the age group 1-14 years, being surpassed only by accidents. However, even in those countries in which paediatric cancer is attracting increasing interest, the disease is relatively uncommon, and the number of cases seen by any one physician, even in a large general hospital, is often limited to one or two a year. The widely held view by parents and even by many doctors that cancer in childhood is usually untreatable and inevitably fatal is no longer tenable. With improvement in the therapeutic response or in the actual survival rates of children with such lesions as Wilms' tumour, brain tumours, rhabdomyosarcomas, Ewing's sarcoma, retinoblastoma, lym­ phoma and even leukaemia, there is a real hope of achieving a substantial reduction in the mortality of childhood cancer. Paediatric oncology is, in fact, providing a vigorous stimulus to the much wider field of cancer treatment and research, and is demonstrating the advantages of a multi-disciplinary cooperation in the management of this disease.