ABSTRACTBackground and AimCurrent pediatric renal tumor treatment protocols allow for nephron‐sparing surgery (NSS) for unilateral disease only under strict conditions. Oncological guidelines do not account for surgical feasibility, however, possibly reducing the utilization of NSS. To potentially change this, a definition of surgical feasibility is required. This study aimed to define surgical consensus statements for the assessment of patients with Wilms tumor (WT) for NSS.MethodsA Delphi study was performed inviting 34 potential experts. Surgeons were asked to answer the questionnaires without considering their current treatment protocol. The first questionnaire contained five open‐ended questions regarding surgery, oncology, contraindications for NSS, technique, and organization. Follow‐up questionnaires contained closed‐ended statements based on previous answers.ResultsEleven surgeons were included in the expert panel and continued with three follow‐up questionnaires containing 72 statements in total. A median of seven (3 minimum to 10 maximum) NSS procedures were performed per year in the hospitals of the experts. NSS for nonsyndromic unilateral WT patients can be surgically considered if they receive 4 weeks of neoadjuvant chemotherapy, have a preoperative tumor volume of less than 200 mL, and if partial nephrectomy with wide resection margin (>5 mm) can be performed. In keeping with organizational guidelines, among COG surgeons, NSS was not advocated for patients with nonsyndromic unilateral WT.ConclusionsUsing a Delphi method, surgical experts defined consensus statements regarding NSS for patients with WT to define surgical feasibility in future treatment protocols and expand the utilization of oncologically appropriate NSS.