Primary thalamic tumors are rare and bilateral thalamic tumors are even rarer. The incidence, clinical manifestations, natural history and prognosis of primary bilateral thalamic gliomas (PBTT) remain relatively obscure. In this article, four cases of bilateral thalamic gliomas are discussed and the available literature is reviewed. We conclude that primary bilateral thalamic tumors are distinct lesions, as proven by their specific neuroradiological and metabolic properties, unresponsiveness to radiotherapy and chemotherapy as well as a rapidly fatal clinical evolution. Early diagnosis and prompt therapy may delay the devastating effects of this tumor.