For normal functioning, the brain requires an adequate supply of blood. The components of normal brain vasculature are collectively referred to as the neurovascular unit. When the brain develops pathology, the structural and functional components of brain vasculature become compromised. This is evidenced in the case of neoplasia where the integrity of the vasculature is co-opted to further the neoplastic processes that require exponential blood resupply in order to facilitate the diffusion radius of tumor growth. Glioblastoma changes the brain vasculature in such a way that advances the tumor’s progress while making it more resistant to standard modes of treatment. While the brain vasculature is changed as a result of glioblastoma growth and progression, it is also changed to advance the invasiveness of the tumor. The diagnostic criteria for glioblastoma is correlated with advanced neovascularization processes that change the previously existing vasculature into that which is morphologically atypical and in a dysfunctional state. Advancing therapies to treat glioblastoma must understand normal brain vasculature and how it is changed as a result of tumor growth.