For more than 10 years, children at our national center for pediatric liver transplantation (LT) have been treated with Molecular Adsorbent Recirculating System (MARS) liver dialysis as a bridging therapy to high-urgency LT. Treatment was reserved for 20 patients with the highest degrees of hepatic encephalopathy (HE; median grade?=?3.5). Death from neurological sequelae was considered imminent for these patients, and this was further reflected in significantly higher international normalized ratios and ammonia levels and worse prognostic liver indices (Model for End-Stage Liver Disease/Pediatric End-Stage Liver Disease scores and liver injury units) in comparison with 32 wait-listed patients who did not receive MARS dialysis. MARS therapy was generally well tolerated, with a reduction in thrombocytes and hemorrhaging as the most common side effects. HE improvement was documented in 30% of the treated patients, but progression to grade IV encephalopathy occurred in 45% of the patients despite the treatment. Serum ammonia, bilirubin, bile acid, and creatinine levels significantly decreased during treatment. Eighty percent of MARS-treated patients survived to undergo LT, and their survival was equivalent to that of non-MARS-treated patients with severe liver failure (69%, P?=?0.52). The heterogeneity between MARS-treated patients and non-MARS-treated patients in our cohort precluded a statistical evaluation of a benefit from MARS for patient survival. Our data demonstrate the safety of MARS even in the most severely ill patients awaiting LT, but strategies that promote the more rapid and widespread availability of high-quality donor organs remain of critical importance for improving patient survival in cases of severe acute liver failure.? 2015 American Association for the Study of Liver Diseases.