Abstract: Objective : To investigate the clinical features and methods used to diagnose and treat gliomatosis cerebri (GC). Methods : Seventeen patients with GC that were diagnosed and treated in Navy General Hospital ofPLA from January 1989 to October 2007 and in China-Janpan Union Hospital from January 2005 to December 2007 were retrospectively analyzed. Results : The clinical manifestations of these 17 patients were variable. The main clinical manifestations included headache, mental status changes, seizure and hemiparalysis.Radiological examination revealed diffuse lesions that produced hypodense signal on CT, a hypo- or isointense signal on T1WI, and a scattered diffuse hyperintense signal on T2WI. Contrast enhancement was absent or minimal. MRS revealed increased choline (Cho)/creatine (Cr) and choline (Cho)/N-acetylaspartate(NAA) ratios in tumors compared with normal brain tissues. Histological examination revealed the widespreadinfiltration of neoplastic glial cells with minimal destruction of pre-existing structures. All cases were astrocytomas including 3 cases of grade Ⅰ, 8 cases of grade Ⅱ, 2 cases of grade Ⅱ-Ⅲ, and 4 cases of grade Ⅲ.The median survival was 9 months (ranged from 21 days to 24 months). Conclusion : When patients havesymptoms and neuroimaging provides MRI evidence of a diffuse infiltrative process involving more than twocerebral lobes that extends to infratentorial structures, a diagnosis of GC should be considered. Stereotacticbiopsy is a powerful and safe method to diagnose GC. Surgery is not a suitable option for GC. Radiotherapy,chemotherapy and ¹²⁵I seed brachytherapy seem to be helpful, but the median survival is short and the prognosis is still poor.