Intractable fever in cancer patients is problematic and the causes of this fever can be diverse. Paroxysmal persistent hyperthermia after sudden mental change or neurologic deficit can develop via autonomic dysregulation without infection or any other causes of fever. Paroxysmal hyperthermic autonomic dysregulation is a rare disease entity. It manifests as a form of paroxysmal hypertension, fever, tachycardia, tachypnea, pupillary dilation, agitation and extensor posturing after traumatic brain injury, hydrocephalus, brain hemorrhage or brain neoplasm. We recently experienced a case of paroxysmal hyperthermia following intracerebral hemorrhage along with brain neoplasm. Extensive fever workups failed to show an infectious or inflammatory source and/or hormonal abnormality. Empirical treatments with antibiotics, antipyretics, morphine, steroid and antiepileptic agents were also ineffective. However, Propranolol, a lipophilic beta-blocker, successfully controlled the fever and stabilized the patient. Fever in cancer patients is a common phenomenon, but a central origin should be considered when the fever is intractable. Propranolol is one of the most effective drugs for treating paroxysmal hyperthermia that is due to autonomic dysregulation.