Veno-occlusive disease (VOD) is a rare complication of chemotherapy in children with cancer. In the literature successful treatment of severe VOD has not been well determined. The authors report a 5-year-old boy with Willms tumor whose condition was complicated with VOD while receiving chemotherapy. He was treated successfully with high-dose methylprednisolone. After therapy, the clinical signs of VOD, such as abdominal ascites, oliguria, and jaundice, disappeared without any adverse effects of therapy.