Glioblastoma multiforme (GBM) is a neoplasm of the astrocytes and is the most malignant of all primary adult brain tumors. Unfortunately, GBM is the most frequently occurring of all primary brain tumors too. Despite recent advances in cancer therapeutics and neurological surgery, the prognosis of GBM remains grave. Most patients with this disease succumb to death within 1 year of diagnosis. Though these tumors occur mostly in adults, no age is immune. There is a slight male predominance. Most of the tumors are supratentorial. The tumor cells diffusely infiltrate into the brain parenchyma and hence the tumor is not well delineated from the adjacent brain parenchyma. The tumor consists of neoplastic cells having highly pleomorphic nuclei showing a high proliferation index. However, diagnosis, according to the World Health Organization (WHO) criteria, depends on the presence of tumor cell necrosis and/or microvascular proliferations (angiogenesis) within the tumor.