Objectives To compare paediatric healthcare practice variation among five European emergency departments (EDs) by analysing variability in decisions about diagnostic testing, treatment and admission. Design and population Consecutive paediatric visits in five European EDs in four countries (Austria, Netherlands, Portugal, UK) were prospectively collected during a study period of 9–36 months (2012–2015). Primary outcome measures Practice variation was studied for the following management measures: lab testing, imaging, administration of intravenous medication and patient disposition after assessment at the ED. Analysis Multivariable logistic regression was used to adjust for general patient characteristics and markers of disease severity. To assess whether ED was significantly associated with management, the goodness-of-fit of regression models based on all variables with and without ED as explanatory variable was compared. Management measures were analysed across different categories of presenting complaints. Results Data from 111 922 children were included, with a median age of 4 years (IQR 1.7–9.4). There were large differences in frequencies of Manchester Triage System (MTS) urgency and selected MTS presentational flow charts. ED was a significant covariate for management measures. The variability in management among EDs was fairly consistent across different presenting complaints after adjustment for confounders. Adjusted OR (aOR) for laboratory testing were consistently higher in one hospital while aOR for imaging were consistently higher in another hospital. Iv administration of medication and fluids and admission was significantly more likely in two other hospitals, compared with others, for most presenting complaints. Conclusions Distinctive hospital-specific patterns in variability of management could be observed in these five paediatric EDs, which were consistent across different groups of clinical presentations. This could indicate fundamental differences in paediatric healthcare practice, influenced ...