A rare case of intracranial hemorrhage proved associated with von Willebrand's disease was reported. A 4-year-old girl fell down and hit her occipital region against a small wooden case. Soon after she cried for a few minutes, but she gradually became unconscious. Four hours later she was brought to our hospital. On admission she was semicomatose with left hemiparesis. There was no evidence of head injury and plain skull films were normal. CT scan disclosed a hematoma in the right basal ganglia with a ventricular hemorrhage. No vascular malformations were seen on the carotid angiogram. Immediate aspiration of intraventricular hematoma and ventricular drainage were performed bilaterally by a frontal approach. After the operation she recovered consciousness dramatically, and on the following morning she had a clear consciousness. One week later ventriculo-peritoneal shunt was performed. There were no episodes of abnormal bleeding in her past or her family histories. But a prolonged bleeding time was recognized by a routine laboratory examination on admission. The clotting time, platelet count and prothrombin time were normal. As further hemostatic study and factor VIII assay demonstrated the decreased platelet retention rate (Saltzman test), the decreased ristocetin induced platelet aggregation rate (RIPA), and the decreased levels of Coagulant factor VIII (VIII: C), factor VIII-related antigen (VIIIR: AG) and von Willebrand factor (VIII: WF), she was diagnosed as von Willebrand's disease. Fortunately we could perform the operation safely and did not experience the troublesome postoperative bleeding without specific therapy. She was discharged one month later with no neurological deficits and returned to her normal life.