This study suggests' that to locate the problems within the child and attribute them to the brain injury' or cognitive deficits as a result, is inadequate for a considered assessment, formulation and intervention process. The Primary Objective ofthis study is to identify which variables predict long-term post-injury psychological adjustment following a TBI. The study was divided into two sections. The Research Design of the first section was the parametric and non-parametric multivariate analysis of the neuropsychological cognitive functioning, schoolfunctioning, behavioural adjustment and the development of novel behavioural and learning difficulties post-injury based on the independent variable of severity of injury. The second section of the study utilised regression analysis and employed the cognitive functioning variables as a block of predictor variables along with five other blocks namely; injury mediated variables, family demographics, parental health, family functioning and emotional adjustment to assess psychological adjustment outcomes based on the outcome measures of the first section. Eighty-nine 6-12 year old children at time of testing, at least one year post-injury were recruited. Standardised neuropsychological cognitive sub-scales were utilised to assess cognitive functioning. Teacher completion of the CBRSC provided a measure of school functioning. Parental completion of the SDQ for each participant, and their sibling, and reporting of novel behavioural and learning difficulties provided a measure of behavioural adjustment at home. The Main Outcomes and Results indicate significant across and between group differences on cognitive functioning and the three outcome measures. The regression analysis would indicate that a significant number of family functioning variables, injury mediated variables and cognitive functioning variables predict long-term psychological adjustment post-injury. The main Conclusions indicate that consideration of the interacting potential of both intrapersonal deficits and interpersonal processes is required to enable an idiosyncratic assessment, formulation and intervention best suited to meet the child's needs.