Objective: The Behaviour Assessment System for Children, Third Edition (BASC-3) is a rating scale for screening emotional and behavioural disorders in children and adolescents commonly utilised in Australia but relies on a US normative sample. This study assessed the cross-cultural validity of the BASC-3 by evaluating the original factor structures of the BASC-3 Teacher Rating Scale Children (TRS-C) and Parent Rating Scale Children (PRS-C) with a clinical sample of Australian children. This study hypothesised that the factor structure of the BASC-3 TRS-C and PRS-C would yield acceptable or good fit indices among the Australian sample. Method: Analyses were conducted on parent and teacher ratings of 716 children (298 children for the TRS-C and 418 children for the PRS-C) with a mean age of 8.63 (SD = 1.54) from a psychology training clinic in Melbourne, Australia. Single-factor congeneric modelling and second-order confirmatory factor analyses examined how well the TRS-C and PRS-C factor structure fit the Australian data. Results: Good and acceptable model fit and significant factor loadings were found in the single-factor congeneric modelling and second-order factor modelling. Conclusions: The results provide supporting evidence of the cross-cultural validity of the BASC-3 TRS-C and PRS-C among Australian children presenting with clinical challenges.