This is an update of the Cochrane systematic review of shared decision-making (SMD) making published in 2013. Children's rights to have their views heard in matters that affect their lives are now well established since the publication of the UN Convention treaty (1989). Children with cancer generally prefer to be involved in decision-making and consider it important that they have the opportunity to take part in decision-making concerning their health care, even in end-of-life decisions. There is considerable support for involving children in healthcare decision-making at a level commensurate with their experience, age and abilities. Thus, healthcare professionals and parents need to know how they should involve children in decision-making and what interventions are most effective in promoting SDM for children with cancer.