Recent research has found child pain-related injustice appraisals to be associated with adverse pain-related outcomes. However, this evidence is mainly based on research using a measure developed for adults in the context of accident-related injuries, which may not translate to paediatric pain populations. Research on the phenomenology of child pain-related injustice appraisals is lacking. This study aimed to examine the phenomenology of pain-related injustice appraisals among both pain-free children and children living with chronic pain, to compare and contrast their experiences. Two focus groups were held with pain-free children (n = 16), and three focus groups were held with paediatric chronic pain patients attending a rehabilitation centre (n = 15) in Belgium. Interpretative phenomenological analysis was applied. Two injustice-related themes were generated from the focus groups with pain-free children: (1) 'Someone else is at fault' and (2) 'I am in pain and he is not'. Two injustice-related themes were generated from the focus groups with paediatric chronic pain patients: (1) 'People don't see my pain' and (2) 'I am missing out because of my pain'. This study offers the first exploration of the phenomenology of child pain-related injustice appraisals in both pain-free children and paediatric pain patients. Findings highlight the interpersonal nature of lived injustice experiences caused by chronic pain, which is not fully captured by existing child pain-related injustice measures. Findings further suggest that pain-related injustice notions may not be extrapolated from a chronic to an acute pain context. The current study offers the first exploration of the phenomenology of child pain-related injustice appraisals in both pain-free children and paediatric chronic pain patients. Findings highlight the interpersonal nature of injustice appraisals that are specific to the experience of chronic rather than acute pain. These appraisals are not fully captured by current child pain-related injustice measures.