The imperative to undertake randomised trials in children arises from extraordinary advances in basic biomedical sciences, needing a matching commitment to translational research if child health is to reap the benefits from this new knowledge. Unfortunately, many prescribed treatments for children have not been adequately tested in children, sometimes resulting in harmful treatments being given and beneficial treatments being withheld. Government, industry, funding agencies, and clinicians are responsible for research priorities being adult-focused because of the greater burden of disease in adults, coupled with financial and marketing considerations. This bias has meant that the equal rights of children to participate in trials has not always been recognised. This is changing, however, as the need for clinical trials in children has been increasingly recognised by the scientific community and broader public, leading to new legislation in some countries making trials of interventions mandatory in children as well as adults before drug approval is given. Trials in children are more challenging than those in adults. The pool of eligible children entering trials is often small because many conditions are uncommon in children, and the threshold for gaining consent is often higher and more complex because parents have to make decisions about trial participation on behalf of their child. Uncertain about what is best, despite supporting the notion of trials in principle, parents and paediatricians generally opt for the new intervention or for standard care rather than trial participation. In this review, we explore issues relating to trial participation for children and suggest some strategies for improving the conduct of clinical trials involving children.