Non-alcoholic fatty liver disease (NAFLD), the liver manifestation of the metabolic syndrome, is now considered to be the commonest liver problem in the western world. This apparent ‘epidemic’, coupled with an accumulating body of evidence that a significant proportion of patients with NAFLD can progress to cirrhosis, liver failure and hepatocellular carcinoma (HCC), has - perhaps not surprisingly - led to an exponential growth in clinical and basic studies investigating all aspects of this hitherto largely ignored disease. The result is a vast increase in understanding of the natural history, clinical features and pathophysiology of NAFLD over the last five years which has now begun to inform the development of rational management strategies.