To investigate usefulness of 3D printing for preoperative evaluations, student and resident education, and communication with parents or guardians of patients with pediatric retroperitoneal tumors. Ten patients planning retroperitoneal tumor resection between March and November 2019 were included. Preoperative computed tomography (CT) images were used for 3D reconstruction and printing. Surveyed items were understanding of preoperative lesions with 3 different modules (CT, 3D reconstruction, and 3D printing) by students, residents, and specialists; satisfaction of specialists; and comprehension by guardians after preoperative explanations with each module. The median age at operation was 4.2 years (range, 1.8–18.1), and 8 patients were diagnosed with neuroblastoma. The 3D printing was the most understandable module for all groups (for students, residents, and specialists, P = 0.002, 0.027, 0.013, respectively). No significant intraoperative adverse events or immediate postoperative complications occurred. All specialists stated that 3D printing enhanced their understanding of cases. Guardians answered that 3D printing were the easiest to comprehend among the 3 modules (P = 0.007). Use of 3D printing in treatment of pediatric patients with retroperitoneal tumors was useful for preoperative planning, education, and parental explaining with obtaining informed consents.