Acute liver failure has a mortality rate in excess of 80%. Most deaths are attributed to brain edema with intracranial hypertension and herniation of structures, where ammonium plays a major role in its generation. We report an 18 year-old female with a fulminant hepatic failure caused by virus A infection. The patient developed a profound sopor and required mechanical ventilation. A CT scan showed the presence of brain edema and intracranial hypertension. A Raudemic catheter was inserted to measure intracranial pressure and brain temperature. Intracranial hypertension became refractory and intravascular hypothermia was started, reducing brain temperature to 33 degrees C. Seventy two hours later, a liver transplantation was performed. After testing graft perfusion, rewarming was started, completing 122 hours of hypothermia at 33 degrees C. The patient was discharged in good conditions after 69 days of hospitalization.