This report describes the case of a 10-month-old boy who was diagnosed to have kaposiform hemangioendothelioma (KHE) with Kasabach-Merritt syndrome (KMS), which is a rare pediatric vascular tumor with a high mortality rate. Although both KHE with KMS were resistant to various therapies, such as oral prednisolone, sclerotherapy, and chemotherapy, repeated radiation therapy with methylprednisolone pulse therapy did reduce the volume of KHE and improved the symptoms of KMS. Unfortunately, a regrowth of KHE with KMS was observed 4 months after the cessation of treatment and the patient thereafter died from an intracranial hemorrhage and Pneumocystis carinii pneumonia, which is a complication related to repetitive radiation and steroid therapy. A histopathologic examination of autopsy specimens confirmed a diagnosis of KHE and immunohistologic staining was positive for vascular endothelial growth factor receptor (VEGFR)-2 and VEGFR-3. These findings may provide the rationale to further investigate the role of VEGFRs in the pathogenesis of KHE and also to elucidate its prognostic value, along with the application of inhibitors for VEGFRs for the treatment of refractory KHE.