In this study, Child Behaviour Checklist (CBCL/4-18) and Youth Self Report (YSR) data was collected for 11 to 15 year old New Zealand adolescents, and compared with U.S. normative data to determine the appropriateness of using U.S. norms in the New Zealand context. Forty-two parents and 51 students completed the CBCL/4-18 and YSR questionnaires respectively. Comparison of CBCL/4-18 mean scale scores showed that New Zealand girls scored significantly lower than U.S. girls on the Withdrawn scale (less withdrawn), and New Zealand boys scored significantly higher on the School Competence scale (more competent). New Zealand - U.S. comparison of YSR mean scale scores showed that New Zealand boys scores significantly lower than U.S. boys on the Withdrawn, Anxious/Depressed, Attention, Internalising and Total Problem scales. New Zealand girls scores lower on the Anxious/Depressed and Internalising scales. The study also compared the responses of students who have not experienced traumatic brain injury (TBI) with those obtained form students who have previously experienced TBI, to determine whether the CBCL/4-18 is biased by the symptoms of neuropathology, masking as psychopathology. Boys who have experienced TBI scores higher on the Somatic, Thought, Attention, Delinquent, Aggressive, Externalising and Total Problem scales, and lower on all the competence scales, compared with boys who have not experienced TBI. Girls who have experienced TBI scored higher on the Withdrawn, Social, Attention, Aggressive and Total Problem scales, and lower on the Activities, School and Total Competence scales compared to uninjured girls. When comparing YSR mean scale scores for New Zealand boys and girls, boys scored significantly lower than girls on the Withdrawn, Somatic, Internalising and Total Problem scales. Considering the small sample sizes, these results should be viewed with caution, and future research, involving more participants of a wider age range, could contribute valuable information.