Background: COVID-19 was declared a global health emergency. Since children are less than 1% of reported cases, there is limited information to develop evidence-based practice recommendations. The objective of this study was to rapidly gather expert knowledge and experience to guide the care of children with chronic kidney disease during the COVID-19 pandemic. Methods: A four-round multi-center Delphi exercise was conducted among 13 centers in 11 European countries of the European Pediatric Dialysis Working Group (EPDWG) between March, 16th and 20th 2020. Results were analyzed using a mixed methods qualitative approach and descriptive statistics. Results: Thirteen COVID-19 specific topics of particular need for guidance were identified. Main themes encompassed testing strategies and results (n = 4), changes in use of current therapeutics (n = 3), preventive measurements of transmission and management of COVID-19 (n = 3), and changes in standard clinical care (n = 3). Patterns of center-specific responses varied according to regulations and to availability of guidelines. Conclusions: As limited quantitative evidence is available in real time during the rapid spread of the COVID-19 pandemic, qualitative expert knowledge and experience represent the best evidence available. This Delphi exercise demonstrates that use of mixed methodologies embedded in an established network of experts allowed prompt analysis of pediatric nephrologists' response to COVID-19 during this fast-emerging public health crisis. Such rapid sharing of knowledge and local practices is essential to timely and optimal guidance for medical management of specific patient groups in multi-country health care systems such as those of Europe and the US.