Preoperative Wilms tumor rupture is a challenge for tumor management as it may require upstaging. Tumor spillage of nephroblastoma may seriously affect the prognosis. The following study is a case report of preoperative Wilms tumor rupture in the left kidney of a child, resulting from blunt force trauma. The child was operated on with no prior chemotherapy. Wilms tumor rupture was confirmed intraoperatively. Nephroblas-toma was classified as stage III and the child was assigned to oncological treatment, comprising chemotherapy and radiotherapy. Postoperative histopathology, however, did not confirm the rupture and was indicative of stage I.