BACKGROUND: The Molecular Adsorbent Recirculating System (MARS) is a novel extracorporeal technique for liver support. We report the clinical results in the first 13 patients with severe liver failure treated at our institution. Methods: Patients with acute or acute on chronic liver failure of various aetiologies were treated with varying numbers of MARS sessions of six hours duration. Results: Mean APACHE II score was 18. In general, patients with multiple organ failure faired poorly even with MARS treatment. Five patients (38%) survived the hospitalisation. Eight patients (62%) fulfilled criteria for UNOS type I or 2 A status. Two of these patients survived. Five patients had a UNOS 2B status and three survived. In proportion, patients with severe itch, patients with primary non-function and those where MARS was used as a bridge to transplantation seemed to profit most from the treatment. The median reduction in bilirubin concentrations after the treatment period was -28.2%. In survivors, the median reduction was -37.7% and in patients who died was -15.9%. The median encephalopathy score improved from 1.7 to 0.5. Conclusion: The molecular adsorbent recycling system (MARS) might be lifesaving in patients with severe liver failure of different aetiologies.