Prognostic models are useful to estimate disease severity, establish expected survival in a specific situation, and calculate the risk of certain medical interventions. Of all the scores described in liver cirrhosis, those with the widest clinical applicability are the Child-Pugh classification and the model for end-stage liver disease (MELD). Although the Child-Pugh classification was used for many years to stratify patients and select those that can safely undergo liver surgery, currently this classification has been substituted by the MELD. This model uses only three simple and objective variables and has consequently become the most widely used instrument, especially to fix priorities when allocating organs in liver transplantation. Nevertheless, this model has some limitations since some indications for liver transplantation (hepatocarcinoma, metabolic diseases, etc.) and certain comorbidities in patients with cirrhosis (hepatic encephalopathy, hyponatremia, refractory ascites) are not well represented in the MELD.