Children and adolescents with traumatic brain injury (TBI) can experience impaired self-awareness, or difficulty in accurately perceiving their personal abilities. This study aimed to identify the neuro-developmental and socio-environmental factors associated with self-awareness impairment and determine how self-awareness is associated with psychosocial functioning. Parents and their children age 8–16 years with TBI (n = 107, 65.4% male, mean [M] age = 12.66 years, standard deviation [SD] = 2.6 years) were consecutively recruited from an outpatient clinic over a 4-year period. Children completed the Paediatric Awareness Questionnaire (PAQ) to report their functional abilities, and the Beck Youth Inventories to report their self-concept, and anxiety and depression symptoms. Parents completed the PAQ and measures of family functioning, parenting style, and children's emotional and behavioral problems. Self-awareness impairments were defined as more negative parent-child discrepancy scores on the PAQ. Younger age at injury, more severe injury, and more family dysfunction were significantly associated with poorer self-awareness. Poorer self-awareness was associated with worse parent-rated child adaptive functioning and emotional and behavioral problems. However, poorer self-awareness was also significantly associated with more positive self-concept and fewer symptoms of depression and anxiety as rated by children. Overall, impaired self-awareness seems to be both a liability and a benefit depending on the reporter (parent or child) and outcome of interest (adaptive function/behavior or self-concept/mood). [ABSTRACT FROM AUTHOR]