Objectives: To examine young people's and parents' accounts of communication about cancer in childhood. Design: Semistructured interviews analysed using the constant comparative method. Setting: Paediatric oncology unit. Participants: 13 families, comprising 19 parents (13 mothers, six fathers) and 13 patients aged 8­-17 years, recruited from one paediatric oncology unit. The patients had cancer or brain tumour. Results: Most parents described acting in an executive-­like capacity, managing what and how their children were told about their illness, particularly at the time of diagnosis. Their accounts were shaped by concerns to manage their identity as strong and optimistic parents and to protect their child's wellbeing. The patients identified elements of their parents' role that both facilitated and constrained their communication, and while they welcomed their parents' involvement, some expressed unease with the constraining aspects of their parents' role. Some young people described feeling marginalised in consultations and pointed to difficulties they experienced in encounters with some doctors. Conclusions: There are difficulties in managing communication with young people who have a chronic, life threatening illness. Health professionals need to be aware of how the social positioning of young people (relative to adults) and the executive role of parents can contribute to the marginalisation of young people and hamper the development of successful relationships between themselves and young patients. ; Also available from the BMJ website at http://www.bmj.com