In daily paediatrics, drugs are commonly used off-label, as they are not approved for children. Approval is lacking because the required clinical studies were limited to adults in the past. Without clinical studies, evidence-based recommendations for drug use in children are limited. In the meantime, paediatric regulation came into force where the approval of new drugs requires clinical studies in children. Still, most of the drugs currently prescribed to children are not yet covered by this new regulation. Information on drug dosing in children can be found in different handbooks, databases, and scientific publications but the dosing recommendations can differ considerably. Accordingly, prescribing medicines to children remains a challenge. To improve drug safety and efficacy in children and assist the prescribers, stakeholders in Swiss paediatrics started a pilot project, supported by the Federal Office of Public Health, with the aim to create a database, providing healthcare professionals with so called “harmonised” dosage recommendations based on national consensus. A standardised process for dosage harmonisation was defined, guided, and documented in an electronic tool, developed for this purpose thereby integrating the latest available scientific evidence and best clinical practice for optimal dosage recommendations. As proof of principle, a total of 102 dosage recommendations for 30 different drugs have been nationally harmonised in the pilot phase considering the current literature and the consent of the most experienced national experts in the field. This approach paved the way for unified national dosage recommendations for children.