The purpose of this pictorial essay is to illustrate the computed tomography and magnetic resonance imaging manifestations of hypoperfusion and hypoxic brain injury in adults, a clinical scenario not uncommon in the emergency room setting. The imaging findings can be subtle or marked depending on the type of injury and the time elapsed from injury to imaging. Accurate recognition of the imaging findings in hypoperfusion and hypoxic injury in adults is important for accurate therapy and family-patient counseling.