Brain perfusion and iomazenil SPECT have been applied for the following three clinical condition in stroke. First, brain perfusion SPECT have established the cerebral blood flow thresholds for the development of infarction or hemorrhage and the results have suggested that pretreatment SPECT can provide useful parameters to increase the efficacy of thrombolysis by reducing hemorrhagic complications. Iomazenil SPECT detects a selective loss of cortical neurons in patients with transient hypoperfused tissue, which is morphologically intact on MRI. Second, reduced cerebrovascular reactivity to acetazolamide determined by quantitative brain perfusion SPECT is significantly associated with an increased risk of stroke recurrence in patients with symptomatic intracranial main trunk occlusion. Combination of brain perfusion SPECT and iomazenil SPECT may accurately detects misery perfusion. Lastly, preoperative measurement of acetazolamide-induced changes in cerebral blood flow using SPECT can identify patients at risk for hyperperfusion after carotid endarterectomy. Iomazenil SPECT detects wide loss of cortical neurons due to cerebral hyperperfusion following carotid endarterectomy.