Cerebral air embolism during pleural lavage is a rare, but potentially fatal complication. We present a case of severe cerebral air embolism that developed during pleural lavage for empyema and was successfully treated by therapeutic hypothermia. A 77-year old male patient with empyema developed severe cerebral air embolism during pleural lavage via a chest tube. Cranial computed tomography and cranial magnetic resonance imaging showed many small bubbles and widespread infarction in the territory of the right middle cerebral artery. The patient received therapeutic hypothermia maintained at 33°C for 24 h and could leave the hospital without delayed sequelae.