BACKGROUND: Combined pH-impedance monitoring has been suggested as the investigation of choice for diagnosing gastro-oesophageal reflux in children. Although it is superior to oesophageal pH monitoring in detecting all types of reflux episodes (acid, weakly acidic and alkaline) with the ability to evaluate symptom association with reflux events, it is still limited by the lack of true paediatric normal value and the high cost involved (equipment and personnel). OBJECTIVE: To produce a position statement on behalf of the Motility Working Group of the British Society of Paediatric Gastroenterology, Hepatology and Nutrition on the indications and practical application of combined oesophageal pH-impedance monitoring in children. METHODS: Up-to-date review of available evidence. RESULTS: This document provides a practical guide to clinician on indications, methods and results interpretation of paediatric multichannel intraluminal impedance pH (MII-pH). CONCLUSIONS: MII-pH is increasingly used by paediatricians as the diagnostic tool for assessing gastro-oesophageal reflux disease and symptom association. There is wide variation in paediatric practice and a need for standardised practice.