MARS (Molecular Adsorbent Recycling System) as a novel hepatic detoxification procedure until orthotopic liver transplantation. We report the case of a 30-year-old man who was admitted because of acute liver failure due to longstanding ethanol abuse. On conservative treatment liver function progressively deteriorated and the patient was listed for orthotopic liver transplantation. Because of a rapidly progressive and clinically severe hepatic encephalopathy together with increasing bilirubin levels (maximum 39 mg/dl) we began intermittent extracorporeal detoxification with the Molecular Adsorbent Recycling System (MARS). Under MARS therapy serum bilirubin decreased significantly (to 20 mg/dl after three cycles) and encephalopathy improved rapidly until the patient was completely oriented. No effect of MARS on liver function could be demonstrated. MARS treatment was successfully continued until a cadaver liver became available after 48 days and the patient was transplanted in good clinical and neurological condition and without complications. MARS represents a novel detoxification technique which, in patients with acute liver failure, can successfully replace hepatic detoxification until orthotopic liver transplantation can be performed.