Non-alcoholic fatty liver disease is regarded as the hepatic manifestation of metabolic syndrome and is an important and common cause of chronic liver disease with a potential to develop end-stage liver disease. While important advances in the pathophysiology have been achieved using genetically modified and diet-induced animal models, in-vitro models have been only recently proposed. These models include primary culture and immortalized cell lines. Here we critically review the characteristics of the in vitro models described, the advantages and limitations of the in vitro approach, and the results derived.