Background: In July 2005, Argentina was the first country after the United States to adopt the MELD system. The purpose of the present study was to analyse the impact of this new system on the adult liver waiting list (WL)., Methods: Between 2005 and 2009, 1773 adult patients were listed for liver transplantation: 150 emergencies and 1623 electives. Elective patients were categorized using the MELD system. A prospective database was used to analyse mortality and probability to be transplanted (PTBT) on the WL., Results: The waiting time increased inversely with the MELD score and PTBT positively correlated with MELD score. With scores >/= 18 the PTBT remained over 50%. However, the largest MELD subgroup with <10 points (n = 433) had the lower PTBT (3%). In contrast, patients with T(2) hepatocellular carcinoma benefited excessively with the highest PTBT (84.2%) and the lowest mortality rate (5.4%). The WL mortality increased after MELD adoption (10% vs. 14.8% vs. P < 0.01). Patients with <10 MELD points had >fourfold probability of dying on the WL than PTBT (14.3% vs. 3%; P < 0.0001)., Conclusions: After MELD implementation, WL mortality increased and most patients who died had a low MELD score. A comprehensive revision of the MELD system must be performed to include cultural and socio-economical variables that could affect each country individually.