What's known on the subject? and What does the study add? Without age being a limiting risk factor, recent reports have shown that almost any version of percutaneous nephrolithotomy (PCNL) can be safely applied in children. As there has been no standardisation in the age categorisation of children, there are inconsistencies among the age subgroups in the current literature., To achieve a standard terminology and thus a common language, the World Health Organization age classification criterion was used in the present study. Based on the findings, we can suggest that PCNL can be applied safely and effectively in children in different age groups., Objectives To present the overall results of paediatric percutaneous nephrolithotomy (PCNL) compared with adults., To present the indications, complications and outcomes of patients treated in the participating centres in the PCNL Global Study, as categorised in different age groups., Patients and Methods The Clinical Research Office of the Endourological Society (CROES) Study was conducted from November 2007 to December 2009, and included 96 centres and > 5800 patients., All children aged≤ 14 years in the PCNL Global Study database were the focus of the study., Results In all, 107 children aged≤ 14 years were included in the analysis., The PCNL procedure was conducted in 13 patients (12.1%) in the supine position; tubeless PCNL was performed in 15 patients (14%); and balloon dilatation was preferred in 22 patients (20.5%). The overall mean operative duration was 97.02 min; blood transfusion rate, fever and stone-free rates were 9%, 14% and 70.1%, respectively., A comparison of the paediatric PCNL cases according to age groups showed no statistically significant differences between the subgroups for patient characteristics, co-morbidities, renal anomalies, or previous surgical history., In the evaluation of the operative details, the mean sheath size and nephrostomy tube size were larger in school-age children than the preschool children (P= 0.01 and 0.002, respectively). There was a difference in the preferred methods for confirming stone-free status, with ultrasonography preferred more in preschool children (P < 0.001)., The PCNL procedure position, puncture site, dilatation method, postoperative tube application, and surgical outcomes were comparable in school-and preschool-age children. While operative details showed some differences between children and adults, the surgical outcomes were comparable., Conclusions A considerable number (45.7%) of the paediatric patients had a previous history of stone intervention., Based on the findings of the present study, we can suggest that PCNL can be applied safely and effectively in children in different age groups., Outcomes appear comparable with those in adults for the success and complication rates, in the presence of substantial indications, appropriate equipment and adequate experience.