Artificial liver support systems (ALS) is a new therapeutic approach for patients with acute liver failure (ALF) or acute-on-chronic liver failure (ACLF). Using this technology patients should have a better chance for regaining their own liver function or for successful bridging to transplantation. Treatment costs in Germany are 10-15,000 EUR per patient. OBJECTIVES: To determine and summarize the scientific evidence on medical efficacy and economic effectiveness of the use of ALS in patients with ALF or ACLF. METHODS: In an extensive systematic literature search in all relevant medical and economic data bases all published studies on ALS were identified and systematically described. All results concerning the treatment of ALF or ACLF were extracted and if possible synthesized to final recommendations. RESULTS: Three different artificial liver support systems could be identified. For BioLogic-DT® neither of the identified studies reported medical or economic benefits. For Prometheus® no randomized controlled studies reporting medical or economic effects are available. For MARS (Molecular adsorbing recirculating system) for patients with ACLF a significant improvement of clinical parameter and 30d-survival could be demonstrated. First health economic studies with short time horizon report costs per QALY of 60,000 EUR and conclude that prolonging the time horizon would improve cost-effectiveness. All studies show methodological limitations. CONCLUSION: The present scientific evidence according to published trials on ALS does not show any medical or economic benefit of the liver support systems BioLogic-DT® and Prometheus®. The limited evidence for the benefit of the system MARS gives hints that ACLF patients might clinically benefit and that cost-effectiveness is acceptable. Future randomized controlled studies with large sample size and health economic models to estimate long term benefits are necessary to confirm these results.