Onconephrology is a new specialized field, and pediatric nephrologists should initiatively and professionally take part in the treatment of children with malignant disease along with the pediatric oncologist and other health care providers. Case: A 3-year-old female patient with advanced neuroblastoma and systemic metastasis, which had a poor prognosis, underwent autologous hematopoietic stem cell transplantation (auto-HSCT) with massive chemotherapy. The complications resulted in acute kidney injury (AKI) requiring continuous hemodiafiltration (CHDF). Although the systemic condition of the patient partially recovered, her renal function did not fully recover and intermittent hemodialysis (IHD) was required. However, she was intolerant to IHD, and sustained low-efficiency dialysis (SLED) was performed for 3 months. Remaining metastases in the bones and end stage kidney disease (ESKD) requiring renal replacement therapy (RRT) made her parents anxious and fearful, which was assisted by much discussion about care and treatment of the patient with healthcare providers including pediatric nephrologist. Her parents eventually chose palliative home care, with peritoneal dialysis (PD) using cycler, due to a small abdominal cavity, after the removal of the neuroblastoma. In pediatric patients with coexisting malignant disease and ESKD, the modalities of RRT should be selected based on the status of the malignant disease and the systemic condition, and should be undertaken with family-centered shared decision-making that respects the rights of pediatric patients.