Metabolic dysfunction-associated fatty liver disease (MAFLD) is a common disease in the population of cardiological, diabetic, and endocrine patients. The diagnosis of MAFLD is important because the presence of this disease has a significant impact on the prognosis related to not only hepatic but, above all, cardiovascular events. In recent years, new criteria for the diagnosis of MAFLD have been adopted, which have significantly simplified the diagnosis of this disease, and in recent months a further division of fatty liver depending on its aetiology has been proposed.