Background: Exploring children’s experiences of a life-threatening or life-limiting diagnosis is essential in offering appropriate care for them. There have been few studies examining these and they are often from the parent’s perspective. Even if adults are frequently unwilling to share information with children, they become aware of their diagnosis and prognosis. The theory of awareness contexts provided a theoretical framework through which it can be understood what children knew about their condition. Aim: To advance the understanding of the experiences of children with a life-threatening or life-limiting condition. Design: A qualitative study using dyadic interviews and thematic analysis. Setting/participants: Ten children between 14 to 17 years old with a life-threatening or life-limiting illness who were supported by a palliative care service in Romania. Interviews were also undertaken with their mothers. Results: Interview data demonstrated that there was a gap in the child’s experience and understanding of their condition compared to their parents. The data produced six major themes: awareness of the illness, death and dying, the spiritual response to illness, the emotional response to illness, striving for normality and independence and coping strategies. The study showed that children can read subtle cues or they may talk with other children to learn about their illness when information is not openly available to them. Conclusions: Children in the study often know more about their condition than their parents realised. Using this understanding, healthcare professionals can advise parents and children about how to communicate with one another which would enable the children to give voice to their thoughts, emotions and experiences. © The Author(s) 2021.