This is the first report of extraneural metastasis of malignant glioma through V-P shunt tube and growth in peritoneal cavity as ascitic form. The patient was a 43-year-old man who was admitted to our hospital with occipital headache. CT scan showed enhanced cystic tumor mass at left temporal lobe. Craniotomy and partial excision of the tumor was done and the histology of tumor tissue showed a malignant astrocytoma. Following this treatment, the patient received the adjuvant therapies of radiation, chemotherapy and immunotherapy with interferon, and also recraniotomy three times. In the mean time, a ventriculo-peritoneal shunt was set up for internal hydrocephalus. One month later, abdominal bulging appeared and yellowish ascites could be obtained with peritoneal tap. In the ascite, tumor cells with glial fibrillary acidic protein were observed at the concentration of 5-10 x 10(4) cells/ml. The patient died three months after extraneural metastasis to the abdominal cavity as ascitic form. At autopsy, solid metastatic mass lesion was not found in extraneural region include abdomen.