The Australian Paediatric Surveillance Unit (APSU) facilitates the conduct of national collaborative research that is consistent with national health priorities, has potential to impact on public health, and addresses gaps in knowledge. Since 1993 paediatricians and other child health specialists have contributed monthly data on rare childhood conditions to the APSU. Over 40 conditions, including infectious diseases, injuries, vaccine-preventable diseases and genetic disorders have been studied. Information on epidemiology, frequency, diagnosis, management and short-term outcomes of these conditions is collected and provides evidence to support changes to clinical practice, prevention policy and allocation of health resources. In this review we give examples of the value of information gathered through the APSU surveillance system in the last 14 years.