<p>In paediatric oncology, ethical dilemmas often arise and includes different perspectives about what is perceived as ethically right care for the child. Ethics Case Reflection (ECR) rounds, a form of Clinical Ethics Support (CES), offer a structured, dialogical approach to facilitate ethical reflection. A Nordic working group on ethics in pediatric oncology offers a training program for healthcare professionals to become facilitators for ECR rounds. The aim of this study was to explore experiences of these facilitator trainees when facilitating ECR rounds in Nordic paediatric oncology. Using classic grounded theory methodology, data were collected through three focus groups with 22 Nordic facilitator trainees and 27 individual interviews with 17 facilitator trainees from Sweden. <i>Carrying the facilitator responsibility</i> is the core category in this study, used to resolve the main concern of delivering a meaningful experience of ethics support and enabling ethically good care for the child. To carry the facilitator responsibility and handle associated challenges, the condition of <i>achieved facilitator confidence</i> and the strategies of <i>allying</i> and <i>undertaking the facilitator role</i> is important. ECR facilitator trainees take their role seriously as they are carrying the facilitator responsibility to deliver a meaningful experience of CES and enable ethically good care for the child. We conclude that this perceived burden of responsibility should be better addressed during future facilitator trainings, emphasising the use of various strategies to decrease this burden and share the responsibility for the ECR together with the ECR participants. Training also needs to strengthen ethical competence to achieve facilitator confidence of the trainees. Further research is needed on what kind of core ethical competencies facilitators of ECR rounds needs.</p>