Diffuse bithalamic glioma is rare entity. A few cases have been described so far. We present the data of 13 patients (both children and adults) with diffuse bithalamic gliomas observed and treated at Burdenko Neurosurgery Institute within the period of 2004-2011. Age of patients varied from 3 to 29 y.o. Bithalamic gliomas appear as symmetric enlargement of both thalami on MRI with frequent spreading to adjacent structures (brainstem, temporal lobes). Histologically they appear as astrocytomas (Grade II-IV). Bithalamic gliomas posess different clinical course. There is no indication for surgical treatment because of diffuse growth of these tumors. Stereotactic biopsy is indicated to verify histological origin. Treatment of bithalamic gliomas confined with radio- and chemotherapy. In cases with obstructive hydrocephalus CSF diverting operations are indicated. Attempts of surgical excision lead to worsening of patient's neurological condition. Most patients with bithalamic gliomas have unfavorable prognosis. Tumors remain stable with adjuvant therapy for a very short period of time in most cases. Benign course of this pathology with long-term follow-up is observed only in a few cases.