In 2005 the National Institute for Health and Clinical Excellence (NICE) published guidance on improving outcomes in children and young people with cancer. The guidance applies to England and Wales only, but has influenced service development in the four countries of the United Kingdom (UK) and the Republic of Ireland. Progress in implementation of the guidance has been slower than anticipated, mainly because of its complexity and scope, particularly in relation to shared care and services for teenagers and young adults. Supplementary guidance has been developed so that commissioners and providers can work towards meeting the required quality standards. The lessons learned in improving cancer services could inform developments in other specialist services for children and young people.