Impaired self-awareness impacts outcomes for individuals with brain injury. Self-awareness is a complex construct, with little known about how its presentation differs across diagnostic groups, or how brain injury-related changes are expressed by individuals in the early phase post-brain injury. This study aims to identify differences and similarities in patterns of self-awareness between patients with different brain injury diagnoses, and provide a clinical account of how individuals with ABI describe changes to themselves arising from brain injury. This is a mixed methods retrospective cohort study involving an audit of medical files that included extraction of data from the Self-Awareness of Deficits Interview. Quantitative and qualitative techniques were used to analyse data from 173 participants. Individuals identified a range of brain injury-related impairments across domains, with greatest difficulty noted with linking impairments to functional implications and setting realistic goals. There were similarities and distinct differences in the expression of changes across diagnostic groups. Two main themes that aligned with self-awareness theory were identified from the data: 1/ Development of self-awareness; and 2/ Dimensions of self-awareness. These interrelated themes demonstrated the multifaceted nature of the clinical presentation of self-awareness, and highlight the need for an individualized approach to cognitive rehabilitation.