Glioblastoma multiforme (GBM) is the most common central nervous system malignancy. It is rapidly progressive with rare opportunity for cure. After three decades of laboratory and clinical research, a newly evolved chemoradiotherapy approach using the alkylating agent temozolomide during and after radiotherapy has resulted in the first significant impact on this disease. Here we discuss the basis for this positive interaction as well as potential mechanisms of resistance to it. Additionally, in the context of current and planned research, we explore approaches to take advantage of this combination and the use of targeted therapies to exploit cell signaling alterations found in GBM. We anticipate that a multimodality approach directed at tumor-specific biology will result in more meaningful advancements in the treatment of this fatal disease.