This article examines the evidence about ‘what works’ in supporting self-care in relation to children or young people with physical and mental health conditions. It is based on two systematic reviews and on research evaluating different self-care support programmes that have been developed in the UK. The authors identify four components for an effective and acceptable self-care programme that nurses can include when developing and providing such support for children and young people with long-term physical and mental health conditions. These are: providing a sense of community, developing knowledge and skills, building independence and confidence, engaging children and young people. The authors highlight the increasingly important role that children’s and mental health nurses can play in supporting young people’s self-care.