Most neurosurgical emergencies involve either diversion of cerebrospinal fluid, control of intracranial pressure, or decompression of brain parenchyma and cranial nerves. The goal of these interventions is to reverse or prevent progression of damage to neural structures. The pathologies that require emergent neurosurgical treatment can develop acutely or may progress over days and reach a critical point of decompensation. Medical management has usually been maximized when the neurosurgeon is called because surgical intervention itself can carry considerable risk. These risks should be weighed heavily against potential benefits and should involve discussions with family. The body of literature for most emergent scenarios continues to evolve and challenge traditional practice. Many interventions are effective and may return patients to full function. However, while neurosurgical procedures can be life-saving, surviving patients may be severely disabled and dependent. All providers involved in clinical decision-making should be familiar with current evidence and guidelines such that an informed, multidisciplinary decision can be made. In this chapter, we present an overview of management for the most common neurosurgical emergencies: spontaneous intraparenchymal hemorrhage, intraventricular hemorrhage, nontraumatic subarachnoid hemorrhage, epidural hematoma, subdural hematoma, severe traumatic brain injury, skull fractures, penetrating cerebral trauma, acute hydrocephalus, cerebral edema, malignant ischemic stroke, intracranial epidural abscess, subdural empyema, pituitary apoplexy, and decompensation from brain tumors. Each section presents key facets of initial workup and management, the role of surgical intervention, postoperative considerations, and the typical intensive care unit (ICU) course. The most recent major US guidelines have been incorporated into the text along with strength of recommendations and levels of evidence.