Although, the recent use of bevacizumab has resulted in significant imaging responses, it appears that the impact on overall survival may be more limited, likely illustrating the fact that imaging responses may not correlate well with overall survival. given that vascular endothelial growth factor (VEGF) the ligand to which bevacizumab binds is responsible for a significant component of the permeability of the blood-brain-barrier (BBB), it will be important to distinguish effects on the BBB from true anti-tumor effects. This paper will illustrate the patterns of responses seen typically on post-Gd and FLAIR MRI. We also illustrate several patterns of tumor progression seen in patients treated with long-term bevacizumab in order to illustrate the range of novel imaging changes being seen in this clinical setting. The addition of bevacizumab to the clinical armamentarium for the treatment of glioblastoma has enhanced clinical outcomes, but it has come with the need to understand the range of imaging effects for this novel targeted therapy.