Introduction: Tension pneumocephalus is a neurosurgical emergency that occurs when subdural air causes a mass-effect over the underlying brain parenchyma. It is often termed the Mount Fuji sign due to an anticipated similarity with an iconic mountain peak in Japan. Case Presentation: We describe an 83-year-old woman with loss of consciousness, severe dizziness, nausea, and vomiting symptoms 20 days after a craniotomy. Conclusions: In this case report we discuss imaging and management of tension pneumocephalus.