Chronic or persistent pain is a growing global health problem. Effective management of pain emerging in childhood may prevent long-term health and vocational consequences. Internationally, paediatric pain services are a limited resource and, as such, must strive to improve equity, outcomes, and value for money. The Paediatric electronic Persistent Pain Outcomes Collaboration (PaedePPOC) is a binational paediatric outcome measurement centre that aims to measure, benchmark, and improve children's specialist pain services in Australasia. This study documents the establishment of PaedePPOC and presents baseline and initial outcome data. Binational consensus meetings determined the measures. Governance structures, collection protocols, information technology, site-specific logistics, and onsite training were achieved within 18 months. Children and parents complete baseline and progress questionnaires. Seven of 10 Australasian services provided data to PaedePPOC, with 1432 patients enrolled until June 2018. At baseline, patients were 12.4 ± (3.0) years, 68% female, 93% Australian-born, and 5% Aboriginal and/or Torres Strait Islander people. Most had moderate-severe functional disability and impaired quality of life, with pain affecting school attendance and employment. Opioid-containing medicines were used often or daily by 16%. Patients completing outcome measures at treatment end reported clinically significant improvement in pain intensity (49% of patients), functional ability (59%), and quality of life (69%). The PaedePPOC initiative has been successfully integrated into children's pain services, yielding timely point-of-care information to support clinicians and families, and valuable binational and service data to inform quality improvement and future sector planning.