Pituitary apoplexy is a clinical syndrome of headache, visual deficits, ophthalmoplegia, and alteration in mental status resulting from the sudden hemorrhage or infarction of a pituitary adenoma. Infarction of a normal gland also may occur in certain circumstances. Its manifestations are variable, ranging from a clinically benign event to a catastrophic presentation with permanent neurologic deficits or even death. It frequently mimics other intracranial processes and, without a high index of suspicion, may be difficult to diagnose. Radiographic studies, particularly CT and MR imaging, are helpful for diagnosis in both the acute and subacute settings. In its most fulminant presentation, prompt neurosurgical decompression is necessary to preserve sight and life. Corticosteroid replacement is also essential in the acute phase because of the high incidence of adrenal insufficiency. Fortunately, however, with proper management most patients may have good outcomes.