Impaired self-awareness is a common consequence following a brain injury that affects engagement in rehabilitation and results in poor long term functional outcomes. Literature regarding self-awareness following a brain injury in childhood is lacking. The aim of this research study was to understand the self-awareness of deficits from a developmental perspective. METHODS:A multiple case study design with fully integrated mixed methodology (QUAN+QUAL). Fifteen children/young people (CYP) with traumatic brain injury (TBI) (5-17 years; 10 male) were recruited and data were collected from CYP, their parents and teachers. Self-report measures included Strengths and Difficulties Questionnaire and Harter Scales. Interview measures included Self-Understanding Interview and Knowledge Interview for Children. A novel method of analysis compared CYP report to parent/teacher report and to normative children's data. Three exemplars showcase this methodology. RESULTS:Within-case and cross-case analysis identified interrupted development of self-awareness following TBI. CYP ratings differed most from parent/teacher ratings in the social and behavioural domains. In relation to the school/learning and physical domains, CYP ratings differed most from normative children's data. The younger children had greater degree of ratings discrepancy across all domains. Seven key themes were aspirations, beliefs, being different, brain injuries, characteristics, participation, and interpersonal interactions and relationships. CONCLUSION:This study is among the first to describe the complexity of self-awareness across a range of functional domains following a brain injury in childhood. New theoretical and clinical perspectives are presented from understanding the importance of typical development and the child's age at injury.