INTRODUCTION: Casemix reimbursement was introduced to Singapore in October 1999 using the Australian National Diagnosis Related Groups Version 3.1 (AN-DRGs 3.1). The possible impact of this classification system on a Singapore Children's Hospital is discussed. MATERIALS AND METHODS: Data on paediatric patients in KK Women's and Children's Hospital (KKH) were drawn from the inhouse Datamart warehouse system, and reviewed with regards to volume of patients, length of stay and charges. Several high cost categories were selected for a more in-depth review and discussed. RESULTS: The classification system and reimbursement method did not take into account the higher cost of treating children, thus penalising the Children's Hospital. The wide variety of cases treated also gave rise to difficulty in obtaining appropriate reimbursement. The lack of severity of illness measures was a drawback in the Diagnosis Related Group (DRG) for ventilated patients. The lack of outcome measures gave rise to potentially inequitable reimbursement in some high cost neonatal DRGs. CONCLUSION: While Casemix is an improvement over previous methods of providing Government funding in Singapore, particular aspects need to be reviewed, and reimbursement criteria refined to ensure equitable funding to Children's Hospital.