Hirschsprung's disease (HD) was introduced into the Australian Paediatric Surveillance Unit (APSU) system in 1996 with the objective to collect data on demographics, incidence, family history, associated anomalies, clinical features, investigation, and surgical treatment in Australia. Children under 15 years of age with HD (confirmed by biopsy) were entered into a database maintained at The Children's Hospital at Westmead in Sydney. Nationwide, 127 children with HD were reported from January 1997 to December 2000, and near-complete information was available on 126. Neonatal presentation was seen in 114 cases (90%), whereas 12 (10%) presented post-neonatally. There was a history of delayed passage of meconium (more than 24 h) in 65 of the 114 patients (57%) who presented in the neonatal period. In those presenting post-neonatally there was no history of delayed passage of meconium. Primary pull-through was performed in 42 of the 82 patients (51%) operated upon. The Soave procedure was performed in 53 of the total 82 (65%) operations and 29 of 42(69%) primary pull-through operations. Pre-operative enterocolitis was seen in 15 of 126 (12%) and postoperative enterocolitis in 17 of 82 (21%) children. The majority of children with HD are diagnosed in the neonatal period (90%). Primary pull-through is becoming more popular (51%). The Soave procedure is the most commonly performed operation (65%) in Australia. Pre- and post-operative enterocolitis is still a significant problem.