During these last 25 years, despite numerous phases III studies, standard of treatment in glioblastoma multiforme (GBM) consisted of surgery and post-operative radiotherapy, while benefit of chemotherapy was a matter of debate. A phase III study, conducted by EORTC and NCI Canada and involving 573 patients, concluded clearly to the benefit of adding temozolomide during and after radiotherapy as adjuvant treatment. Using this schedule, median survival increase from 12,1 to 14,6 months, and 2 year survival rate from 8 to 26%. In the same time, for anaplastic oligodendroglioma (AO) the phase III study conducted by Cairncross, that compared radiotherapy to a schedule that deliver a chemotherapy with PCV followed by radiotherapy, failed to determine a significant benefit on overall survival, despite the particular chemosensitivity of theses tumors. Moreover, these two studies did underlined impact of biological markers (methylation of the promoter of O6 methylguanine DNA transferase (MGMT) gene for GBM and chromosomes 1p and 19q deletion for AO), that may become decisional markers in the future. We review here the new place of chemotherapy in the adjuvant treatment of GBM and anaplastic gliomas, as well as the impact of these pivotal studies on second lines therapies, and future clinical research.