The HGGs are the most common primary brain tumors and graded by the WHO as either grade III or IV. Headache and other symptoms of increased ICP predominate. Imaging typically show a central hypodensity, surrounded by an irregular enhancing ring and extensive edema; some HGGs, especially the WHO grade III gliomas, do not enhance on imaging. The HGGs are aggressive, infiltrating tumors which respond poorly to all treatment modalities despite best available treatment. Median survival for malignant remains dismal; 15 months for glioblastoma, 3-5 years for anaplastic astrocytomas and 2 to 3 years for anaplastic oligodendrogliomas without 1p and 19q loss, and 6 to 7 years for anaplastic oligodendrogliomas with 1p and 19q loss. Currently, maximal safe neurosurgical resection followed by combined radiation and chemotherapy using TMZ has become the standard of care for glioblastoma. Incremental advances in outcomes are likely in the future as molecular genetics of these tumors are better understood and lead to better targeted and individualized therapies.