The Australian Paediatric Surveillance Unit (APSU), established in 1993 to address the paucity of national data on rare childhood disorders, has become an invaluable research resource. It facilitates prospective, active surveillance for a variety of rare disorders, with monthly reporting by ~1500 paediatricians, who are invited to notify incident cases and provide demographic and clinical data. APSU is highly collaborative (used by >400 individuals/organisations), patient-informed and productive (>300 publications). In 30 years, 72 studies have been initiated on rare infections, and genetic, psychological and neurological disorders, and injuries. Return rates of monthly report cards were >90% for 30 years and paediatricians have provided data for >90% of notified cases. Although there are limitations, including case underascertainment in remote regions, APSU often provides the only available national data. APSU has assisted the government in reporting to the WHO, developing national strategies, informing inquiries and investigating disease outbreaks. APSU data have informed paediatrician education, practice, policy, and service development and delivery. APSU was integral in establishing the International Network of Paediatric Surveillance Units (INoPSU) and supporting development of other units. APSU’s expanded remit includes one-off surveys, hospital audits, systematic reviews, studies on the impacts of rare disorders on families, surveillance evaluations, and joint studies with INoPSU members. Paediatricians value the APSU, reporting that APSU data inform their practice. They must be congratulated for an outstanding collective commitment to the APSU, in providing unique data that contribute to our understanding of rare disorders and support optimal, evidence-based care and improved child health outcomes.