BACKGROUND: Children have a right to participate in matters affecting their lives. With increasing regularity, children's perspectives are being sought regarding their health and health care experiences. Though there is evidence that children find play to be one of the 'best' aspects of hospitalisation, studies rarely focus on children's perspectives on play in hospital. METHODS: This qualitative study explored children's lived experiences of play during hospitalisation. Over five months, ethnographic observations were conducted on a paediatric oncology ward as well as interviews with 16 children ages 3-13 years. RESULTS: Using interpretative phenomenological analysis, children's expressions and experiences illuminated three key points: safety and comfort are integral to children feeling able to play in hospital; the value and efficacy of play is decided by children; and that play is a way for patients to be (and be treated as) children first. CONCLUSION: Hospitals can only be child-friendly if children find them friendly. Listening to and integrating children's perspectives in the discourse around the importance of play in hospital is essential for respecting children's rights and delivering person-centred paediatric healthcare.